Add some JSDoc annotations to describe code functionality. (#355)

* lesen-tan initial commit

* update README.md

* tidy up code

* opt for Map<K, V> instead of Object

* Document dev/*

* add docs for deinflector.js

* update deinflector example

* Annotate

* Revert "Merge branch 'development' of https://github.com/Scrub1492/lesen-tan into development"

This reverts commit b92348f702bc031b36f24462adfa940d17f9ecdd, reversing
changes made to 3255e6d963281af3533dcf1e893df39032d29fec.

* Lint error fix

* Lint error fix

2 files changed, 36 insertions, 8 deletions

diff --git a/ext/js/language/deinflector.js b/ext/js/language/deinflector.js
index 537a4556..90ca79ea 100644
--- a/ext/js/language/deinflector.js
+++ b/ext/js/language/deinflector.js
@@ -16,9 +16,17 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+/**
+ * This class deinflects Japanese terms to its dictionary form.
+ */
 export class Deinflector {
     /**
      * @param {import('deinflector').ReasonsRaw} reasons
+     * @example
+     * const deinflectionReasons = JSON.parse(
+     *   readFileSync(path.join('ext/data/deinflect.json')).toString(),
+     * ) as object;
+     * const deinflector = new Deinflector(deinflectionReasons);
      */
     constructor(reasons) {
         /** @type {import('deinflector').Reason[]} */
@@ -26,8 +34,13 @@ export class Deinflector {
     }
 
     /**
-     * @param {string} source
+     * Deinflects a Japanese term to all of its possible dictionary forms.
+     * @param {string} source The source term to deinflect.
      * @returns {import('translation-internal').Deinflection[]}
+     * @example
+     * const deinflector = new Deinflector(deinflectionReasons);
+     * // [{ term: '食べた', rules: 0, reasons: [] }, { term: '食べる', rules: 1, reasons: ['past'] }, { term: '食ぶ', rules: 2, reasons: ['potential', 'past'] }]
+     * console.log(deinflector.deinflect('食べさせられる'));
      */
     deinflect(source) {
         const results = [this._createDeinflection(source, 0, [])];
@@ -88,6 +101,7 @@ export class Deinflector {
     }
 
     /**
+     * Given a list of rules, return the corresponding deinflection rule flags.
      * @param {string[]} rules
      * @returns {import('translation-internal').DeinflectionRuleFlags}
      */
diff --git a/ext/js/language/dictionary-database.js b/ext/js/language/dictionary-database.js
index c47e1e90..ce5041c8 100644
--- a/ext/js/language/dictionary-database.js
+++ b/ext/js/language/dictionary-database.js
@@ -19,6 +19,9 @@
 import {log, stringReverse} from '../core.js';
 import {Database} from '../data/database.js';
 
+/**
+ * This class represents the dictionary database.
+ */
 export class DictionaryDatabase {
     constructor() {
         /** @type {Database<import('dictionary-database').ObjectStoreName>} */
@@ -141,6 +144,7 @@ export class DictionaryDatabase {
     }
 
     /**
+     * Purges the database.
      * @returns {Promise<boolean>}
      */
     async purge() {
@@ -162,6 +166,7 @@ export class DictionaryDatabase {
     }
 
     /**
+     * Deletes a dictionary.
      * @param {string} dictionaryName
      * @param {number} progressRate
      * @param {import('dictionary-database').DeleteDictionaryProgressCallback} onProgress
@@ -225,9 +230,10 @@ export class DictionaryDatabase {
     }
 
     /**
-     * @param {string[]} termList
-     * @param {import('dictionary-database').DictionarySet} dictionaries
-     * @param {import('dictionary-database').MatchType} matchType
+     * Find terms in bulk.
+     * @param {string[]} termList The list of terms to find.
+     * @param {import('dictionary-database').DictionarySet} dictionaries Dictionaries to find the terms from.
+     * @param {import('dictionary-database').MatchType} matchType Matching type.
      * @returns {Promise<import('dictionary-database').TermEntry[]>}
      */
     findTermsBulk(termList, dictionaries, matchType) {
@@ -259,8 +265,9 @@ export class DictionaryDatabase {
     }
 
     /**
-     * @param {import('dictionary-database').TermExactRequest[]} termList
-     * @param {import('dictionary-database').DictionarySet} dictionaries
+     * Find exact terms in bulk.
+     * @param {import('dictionary-database').TermExactRequest[]} termList The list of terms to find.
+     * @param {import('dictionary-database').DictionarySet} dictionaries Dictionaries to find the term from.
      * @returns {Promise<import('dictionary-database').TermEntry[]>}
      */
     findTermsExactBulk(termList, dictionaries) {
@@ -270,6 +277,7 @@ export class DictionaryDatabase {
     }
 
     /**
+     * Find terms by sequence in bulk.
      * @param {import('dictionary-database').DictionaryAndQueryRequest[]} items
      * @returns {Promise<import('dictionary-database').TermEntry[]>}
      */
@@ -280,6 +288,7 @@ export class DictionaryDatabase {
     }
 
     /**
+     * Find term meta in bulk.
      * @param {string[]} termList
      * @param {import('dictionary-database').DictionarySet} dictionaries
      * @returns {Promise<import('dictionary-database').TermMeta[]>}
@@ -291,8 +300,9 @@ export class DictionaryDatabase {
     }
 
     /**
-     * @param {string[]} kanjiList
-     * @param {import('dictionary-database').DictionarySet} dictionaries
+     * Find kanji in bulk.
+     * @param {string[]} kanjiList The list of kanji to find.
+     * @param {import('dictionary-database').DictionarySet} dictionaries Dictionaries to find from.
      * @returns {Promise<import('dictionary-database').KanjiEntry[]>}
      */
     findKanjiBulk(kanjiList, dictionaries) {
@@ -302,6 +312,7 @@ export class DictionaryDatabase {
     }
 
     /**
+     * Find kanji meta in bulk.
      * @param {string[]} kanjiList
      * @param {import('dictionary-database').DictionarySet} dictionaries
      * @returns {Promise<import('dictionary-database').KanjiMeta[]>}
@@ -313,6 +324,7 @@ export class DictionaryDatabase {
     }
 
     /**
+     * Find tag meta in bulk.
      * @param {import('dictionary-database').DictionaryAndQueryRequest[]} items
      * @returns {Promise<(import('dictionary-database').Tag|undefined)[]>}
      */
@@ -323,6 +335,7 @@ export class DictionaryDatabase {
     }
 
     /**
+     * Find tag for title.
      * @param {string} name
      * @param {string} dictionary
      * @returns {Promise<?import('dictionary-database').Tag>}
@@ -343,6 +356,7 @@ export class DictionaryDatabase {
     }
 
     /**
+     * Get dictionary metadata.
      * @returns {Promise<import('dictionary-importer').Summary[]>}
      */
     getDictionaryInfo() {