Make sections collapsible

Author: chingc

README.md

@@ -6,7 +6,11 @@ Go to the [Actions](https://github.com/chingc/tutorial-github-actions/actions) t
 
 ## basic.yml
 
-A basic workflow to do the essentials.
+<details>
+
+<summary>A basic workflow to do the essentials.\</summary>
+
+If you're unfamiliar with GitHub Actions this will help you get started quickly.
 
 - Runs when changes are pushed
 - Runs on a schedule
@@ -18,11 +22,17 @@ A basic workflow to do the essentials.
 
 [.github/workflows/basic.yml](.github/workflows/basic.yml)
 
+</details>
+
 ## branch_name.yml
 
+<details>
+
+<summary>Getting the branch name without 3rd party tools.</summary>
+
 Getting the branch name is a common CI operation. Surprisingly, there's no pre-defined way to get it in GitHub Actions.
 
-This demo shows the simplest way without using 3rd party actions or invoking various tools.
+This demo shows the simplest way without using 3rd party actions or other tools.
 
 It works in most cases, but there are some quirks.
 
@@ -35,9 +45,11 @@ You may also get an unexpected result depending on the event that triggered the
 
 [.github/workflows/branch_name.yml](.github/workflows/branch_name.yml)
 
-## context.yml
+</details>
+
+<details>
 
-Contexts are a way to access information about workflow runs, variables, runner environments, jobs, and steps.
+<summary>context.yml: Access information about workflow runs, variables, runner environments, jobs, and steps.</summary>
 
 This can be helpful for debugging workflow errors or bugs.
 
@@ -47,9 +59,11 @@ This can be helpful for debugging workflow errors or bugs.
 
 [.github/workflows/context.yml](.github/workflows/context.yml)
 
-## env_var.yml
+</details>
+
+<details>
 
-Environment variables and their scopes work as you'd expect in GitHub Actions.
+<summary>env_var.yml: Environment variables and their scopes work as you'd expect in GitHub Actions.</summary>
 
 They're also fairly self-contained, so any changes you make are isolated to the job you're in.
 
@@ -61,17 +75,23 @@ One quirk that can cause confusion is the fact that environment variables define
 
 [.github/workflows/env_var.yml](.github/workflows/env_var.yml)
 
-## github_script.yml
+</details>
 
-GitHub provides an action that lets you easily write javascript directly in your workflow.
+<details>
+
+<summary>github_script.yml: GitHub provides an action that lets you easily write javascript directly in your workflow.</summary>
 
 The action also includes an object with the current workflow context, references to other useful packages, and it's a pre-authenticated octokit/rest.js client.
 
 - Uses [actions/github-script](https://github.com/actions/github-script)
 
 [.github/workflows/github_script.yml](.github/workflows/github_script.yml)
 
-## homebrew.yml
+</details>
+
+<details>
+
+<summary>homebrew.yml: tbd</summary>
 
 If you develop on macOS you're probably familiar with [homebrew](https://brew.sh).  Did you know it's also available on Linux?
 
@@ -81,14 +101,20 @@ This demo shows how you can leverage its power and convenience to install applic
 
 [.github/workflows/homebrew.yml](.github/workflows/homebrew.yml)
 
-## system_path.yml
+</details>
+
+<details>
+
+<summary>system_path.yml: tbd</summary>
 
 Read, write, and modify PATH like any other environment variable. It has the same quirks.
 
 - Modify PATH env var
 
 [.github/workflows/system_path.yml](.github/workflows/system_path.yml)
 
+</details>
+
 ## References
 
 - [GitHub Docs: GitHub Actions](https://docs.github.com/en/actions)