Merge branch 'vh/config-interactive-singlekey-doc' into maint

* vh/config-interactive-singlekey-doc: git-reset.txt: better docs for '--patch' git-checkout.txt: better docs for '--patch' git-stash.txt: better docs for '--patch' git-add.txt: document 'interactive.singlekey' config.txt: 'interactive.singlekey; is used by...