Documentation updates.
* en/merge-strategy-docs:
Update error message and code comment
merge-strategies.txt: add coverage of the `ort` merge strategy
git-rebase.txt: correct out-of-date and misleading text about renames
merge-strategies.txt: fix simple capitalization error
merge-strategies.txt: avoid giving special preference to patience algorithm
merge-strategies.txt: do not imply using copy detection is desired
merge-strategies.txt: update wording for the resolve strategy
Documentation: edit awkward references to `git merge-recursive`
directory-rename-detection.txt: small updates due to merge-ort optimizations
git-rebase.txt: correct antiquated claims about --rebase-merges