add documentation

src/index.ts

@@ -83,7 +83,22 @@ const ALTER_TO_DIV_EXCEPTIONS = new Set(['div', 'article', 'section', 'p'])
 // These are the classes that readability sets itself.
 const CLASSES_TO_PRESERVE = ['page']
 
-type Options = {
+/**
+ * Options for the Readability library. All options are optional.
+ *
+ *   - `debug` (boolean, default `false`): whether to enable logging.
+ *   - `maxElemsToParse` (number, default `0` i.e. no limit): the maximum number of elements to parse.
+ *   - `nbTopCandidates` (number, default `5`): the number of top candidates to consider when analysing how tight the competition is among candidates.
+ *   - `charThreshold` (number, default `500`): the number of characters an article must have in order to return a result.
+ *   - `classesToPreserve` (array): a set of classes to preserve on HTML elements when the `keepClasses` options is set to `false`.
+ *   - `keepClasses` (boolean, default `false`): whether to preserve all classes on HTML elements. When set to `false` only classes specified in the `classesToPreserve` array are kept.
+ *   - `disableJSONLD` (boolean, default `false`): when extracting page metadata, cheer-reader gives precedence to Schema.org fields specified in the JSON-LD format. Set this option to `true` to skip JSON-LD parsing.
+ *   - `serializer` (function, default `$el => $el.html()`) controls how the `content` property returned by the `parse()` method is produced from the root DOM element. It may be useful to specify the `serializer` as the identity function (`$el => $el`) to obtain a cheerio element instead of a string for `content` if you plan to process it further.
+ *   - `allowedVideoRegex` (RegExp, default `undefined` ): a regular expression that matches video URLs that should be allowed to be included in the article content. If `undefined`, the default regex is applied.
+ *   - `linkDensityModifier` (number, default `0`): a number that is added to the base link density threshold during the shadiness checks. This can be used to penalize nodes with a high link density or vice versa.
+ *   - `extraction` (boolean, default `true`): Some libraries are only interested on the metadata and don't want to pay the price of a full extraction. When you enable this option the `content`, `textContent`, `length` and `excerpt` will be `null`.
+ */
+export type Options = {
     debug: boolean
     maxElemsToParse: number
     nbTopCandidates: number