Add Colocate jj And git Directories For Project as a jj TIL

jj/colocate-jj-and-git-directories-for-project.md

@@ -0,0 +1,59 @@
+# Colocate jj And git Directories For Project
+
+When doing a standard clone of a git repository with `jj`, you'll get a copy of
+the project with a `.jj` directory containing the version control information.
+
+```bash
+$ jj git clone git@github.com:jbranchaud/my-repo
+Fetching into new repo in "/path/of/local/repo"
+...
+
+$ exa --tree --all -L 1
+.
+├── .gitignore
+├── .jj
+├── Cargo.lock
+├── Cargo.toml
+└── src
+```
+
+This is fine if I'm completely familiar with using
+[jujutsu](https://martinvonz.github.io/jj/latest/). However, if I'm coming from
+`git` and still learning, then it would be nice to be able to fallback to
+familiar `git` commands when needed.
+
+But without a `.git` directory, I get this:
+
+```bash
+$ git log
+fatal: not a git repository (or any of the parent directories): .git
+```
+
+When cloning a git repo with `jj`, I can instruct it to _colocate_ which means
+that it will create both the `.jj` and the `.git` data directories in the
+project.
+
+```bash
+$ jj git clone --colocate git@github.com:jbranchaud/my-repo
+Fetching into new repo in "/path/of/local/repo"
+...
+
+$ exa --tree --all -L 1
+.
+├── .git
+├── .gitignore
+├── .jj
+├── Cargo.lock
+├── Cargo.toml
+└── src
+```
+
+Now I can run `jj` commands or `git` commands:
+
+```bash
+$ git log
+commit 0c72abbb83657096677f9a3d5ddc7bce20839165 (HEAD, origin/trunk, trunk)
+...
+```
+
+[source](https://martinvonz.github.io/jj/latest/git-compatibility/#co-located-jujutsugit-repos)