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

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1518 TILs and counting..._
+_1519 TILs and counting..._
 
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@@ -41,6 +41,7 @@ _1518 TILs and counting..._
 * [Internet](#internet)
 * [Java](#java)
 * [JavaScript](#javascript)
+* [jj](#jj)
 * [jq](#jq)
 * [Kitty](#kitty)
 * [Linux](#linux)
@@ -569,6 +570,10 @@ _1518 TILs and counting..._
 - [Yarn Commands Without The Emojis](javascript/yarn-commands-without-the-emojis.md)
 - [Yup Schemas Are Validated Asynchronously](javascript/yup-schemas-are-validated-asynchronously.md)
 
+### jj
+
+- [Colocate jj And git Directories For Project](jj/colocate-jj-and-git-directories-for-project.md)
+
 ### jq
 
 - [Combine An Array Of Objects Into A Single Object](jq/combine-an-array-of-objects-into-a-single-object.md)

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)