Add additional demo

Author: stefmolin

demo-notes.md

@@ -13,26 +13,46 @@ Run the demos in VS Code for the combined view of the file contents and the term
 3. Change `workbench.color.theme` to `Light High Contrast` (default `Dark Modern`).
 
 4. Create a fresh virtual environment:
-  
+
     ```shell
     $ conda create --name pre-commit-demo python=3.12
     $ conda activate pre-commit-demo
     ```
 
 5. Disable Copilot completions by clicking the icon in the bottom right of VS Code.
 
+6. Save a PDF copy of the slides to distribute as needed:
+
+   ```shell
+   $ curl -OJ https://stefaniemolin.com/pre-commit-workshop/slides.pdf
+   ```
+
 ## Section 1 demos
 
-### Pre-commit package installation
+### Git hooks demo
 
 1. Branch off of `main` (name it after the event).
-2. With a pre-made virtual environment activated, run `python3 -m pip install pre-commit`.
+2. Run `tree .git/hooks` and discuss output.
+3. Run `less .git/hooks/pre-commit.sample` and discuss output.
+4. Create a version of the file that will get run: `cp .git/hooks/pre-commit.sample .git/hooks/pre-commit`.
+5. Edit the `.git/hooks/pre-commit` file to have `exit 1` near the top (automatic failure).
+6. Attempt to commit the slides PDF to this branch. Discuss why it failed.
+7. Run `rm .git/hooks/pre-commit` to get rid of the automatic failure hook.
+8. Attempt the commit again. Discuss why it succeeds.
+9. Push the changes up so the PDF version of the slides is available for everyone.
+
+### Pre-commit package installation
+
+1. With a pre-made virtual environment activated, run `python3 -m pip install pre-commit`.
+2. Run `pre-commit --version` to show it worked.
 
 ### Install first set of hooks
 
-1. Create `.pre-commit-config.yaml` file copying the contents from the slides.
-2. Run `pre-commit install`.
-3. Commit the `.pre-commit-config.yaml` file.
+1. Show that `pre-commit sample-config` can be used to see what an example looks like, but mention that the version is outdated, and the contents are different than what we will use.
+2. Create `.pre-commit-config.yaml` file copying the contents from the slides.
+3. Run `pre-commit install`.
+4. Run `less .git/hooks/pre-commit` and show that the contents are now coming from `pre-commit` and referencing the `.pre-commit-config.yaml` file.
+5. Commit the `.pre-commit-config.yaml` file.
 
 ### Adding `ruff`