jj-diffedit: add page (#19429)

pages/common/jj-diffedit.md

@@ -0,0 +1,28 @@
+# jj diffedit
+
+> Touch up the content changes in a revision with a diff editor.
+> More information: <https://jj-vcs.github.io/jj/latest/cli-reference/#jj-diffedit>.
+
+- Edit changes in the current revision with a diff editor:
+
+`jj diffedit`
+
+- Edit changes in a given revision:
+
+`jj diffedit {{[-r|--revision]}} {{revset}}`
+
+- Edit changes comparing a "from" revision to a "to" revision:
+
+`jj diffedit {{[-f|--from]}} {{from_revset}} {{[-t|--to]}} {{to_revset}}`
+
+- Edit only specific paths (unmatched paths remain unchanged):
+
+`jj diffedit {{filesets}}`
+
+- Use a specific diff editor:
+
+`jj diffedit --tool {{name}}`
+
+- Preserve content instead of diff when rebasing descendants:
+
+`jj diffedit --restore-descendants`