Update cheatsheets

tldr/git-merge-index

@@ -0,0 +1,29 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# git merge-index
+
+> Run a merge program on files that need merging.
+> More information: <https://git-scm.com/docs/git-merge-index>.
+
+- Merge all files needing resolution using the standard helper:
+
+`git merge-index git-merge-one-file -a`
+
+- Merge a specific file:
+
+`git merge-index git-merge-one-file -- {{path/to/file}}`
+
+- Merge multiple files, continuing on failures:
+
+`git merge-index -o git-merge-one-file -- {{path/to/file1 path/to/file2 ...}}`
+
+- Quietly merge all files with a custom program:
+
+`git merge-index -q {{merge-program}} -a`
+
+- Inspect merge inputs for a file using `cat`:
+
+`git merge-index cat -- {{path}}`