git-sed: add page (#7356)

pages/common/git-sed.md

@@ -0,0 +1,21 @@
+# git sed
+
+> Replace patterns in git-controlled files using sed.
+> Part of `git-extras`.
+> More information: <https://github.com/tj/git-extras/blob/master/Commands.md#git-sed>.
+
+- Replace the specified text in the current repository:
+
+`git sed '{{find_text}}' '{{replace_text}}'`
+
+- Replace the specified text and then commit the resulting changes with a standard commit message:
+
+`git sed -c '{{find_text}}' '{{replace_text}}'`
+
+- Replace the specified text, using regular expressions:
+
+`git sed -f g '{{find_text}}' '{{replace_text}}'`
+
+- Replace a specific text in all files under a given directory:
+
+`git sed '{{find_text}}' '{{replace_text}}' -- {{path/to/directory}}`