DOC: Replace @Appender decorator with inline docstrings for Index.take, Index.repeat, and Index.get_indexer_non_unique

[mateomramos]

• Part of a fix for DOC: Replace @Appender, @Substitution, @doc with inlined docstrings #62437
• This PR removes the @appender doc decorators for: Index.take, Index.repeat, Index.get_indexer_non_unique
• Removes the unused _index_shared_docs["repeat"]
• Added full inline docstring directly into the listed methods
• Also fixes a small typo in the original docstring for Index.take: (“other other” --> “other”).

[mateomramos]

pre-commit.ci autofix

[mroeschke]

Thanks @mateomramos