When working on the subtasks of {T332714}, there were multiple occasions where some of us were unsure what steps are needed and in which order. Therefore, we should make sure the process to do so is documented clearly so that we can more easily onboard new engineers to this occasional chore for our team.
**Acceptance criteria**
- [ ] Add clear and concise documentation related to adding or removing a language to/from Wikibase at https://www.mediawiki.org/wiki/Manual:Adding_and_removing_languages#Wikibase
- [ ] Link any Wikibase-related documentation from README.md on Wikibase.git to ensure easy accessibility.
- [ ] The documentation should cover the following tasks in a step-by-step manner:
- [ ] Adding a monolingual text language code to Wikibase, explaining the availability of the names and mentioning the need to refer to CLDR.
- [ ] Enabling Wikibase label support by explaining why we need to change both Wikibase.git and config files, what each does, and in what order.
- [ ] Making a language code available for WikibaseLexeme.