docs: jj: add initial jj notes

docs/misc/vcs/jj.md

@@ -0,0 +1,19 @@
+# Jujustsu (`jj`)
+
+## Basic Operations
+
+### Status & Log
+
+`jj status`: show current status of the working copy  
+`jj log -r|--revisions <revset>`: show commits of a given revset  
+`jj log -r|--revisions ::@`: show all ancestors of the working copy  
+
+
+### Describing & Creating Commits
+
+`jj describe -m|--message <message> <revset>`: add a description to the working copy  
+`jj new <revset> -m|--message <message>`: create a new commit after `<revset>` with the given description  
+
+### Merging Commits
+
+`jj new <revset-1> <revset-2> ...`: create a new commit after listed parents

mkdocs.yml

@@ -186,6 +186,7 @@ nav:
   - Misc:
     - VCS:
       - Git: misc/vcs/git.md
+      - JJ: misc/vcs/jj.md
     - GraphQL: misc/graph-ql.md
     - RegEx: misc/regular-expressions.md
     - SSH: misc/ssh.md