[Documentation] update documentation for the recent changes

[Real-John-Cheung]

list of recent changed functions:

• [x] isNoun()
• [x] hasWord(): now will also allow plural forms and conjugations, also change of parameter
• [x] pastPart(): will return input if input is already a past participle
• [x] pluralize(): will return input if input is already plural

[dhowe]

@MelodyneedsMoney please update the checkboxes above...

[dhowe]

thanks @MelodyneedsMoney