git-revert: add page (#3151)

pages/common/git-revert.md

@@ -0,0 +1,20 @@
+# git revert
+
+> Create new commits which reverse the effect of earlier ones.
+> More information: <https://git-scm.com/docs/git-revert>.
+
+- Revert the most recent commit:
+
+`git revert {{@}}`
+
+- Revert the 5th last commit:
+
+`git revert HEAD~{{4}}`
+
+- Revert multiple commits:
+
+`git revert {{master~5..master~2}}`
+
+- Don't create new commits, just change the working tree:
+
+`git revert -n {{0c01a9..9a1743}}`