Fix checklists on CONTRIBUTING.md

Author: WWRS

CONTRIBUTING.md

@@ -10,8 +10,8 @@ The standards below are non-exhaustive but I will update them when relevant.
 
 ## Checklist
 
-[] PR contains a single logical change - Avoid bundling many changes together as they're harder to review
-[] Changes and basic functionality are tested
+- [ ] PR contains a single logical change - Avoid bundling many changes together as they're harder to review
+- [ ] Changes and basic functionality are tested
   - Open the HTML locally and verify it renders correctly and does not produce console messages (errors, warnings, logs)
   - If changing anything other than HTML and CSS, test a known working MIDI. I use Snow Halation, whose MIDI is at
     `/test/sno.mid` and TMB is at `/test/sno.tmb`. The 
@@ -20,14 +20,14 @@ The standards below are non-exhaustive but I will update them when relevant.
     - Ensure the preview looks correct
     - Generate the chart and play it in TC
   - If adding a new feature or changing an existing one, test a MIDI that uses the feature
-[] Style matches existing code (See style guide below)
-[] Changelog is updated in the PR
+- [ ] Style matches existing code (See style guide below)
+- [ ] Changelog is updated in the PR
   - Increment the suffix letter for a tiny change that does not impact features, or a bugfix
   - Increment the minor version for a change that adds or alters a feature beyond a bugfix
   - I will determine when to increment the major version
-[] For feature contributions: Contributor is named in the footer - Add your name if it's not already there
+- [ ] For feature contributions: Contributor is named in the footer - Add your name if it's not already there
   - For bugfixes: Github will add your name to the contributors list but you do not get to appear on the page
-[] PR comment contains a summary of the changes and why they are being made
+- [ ] PR comment contains a summary of the changes and why they are being made
   - Example: "Fixes bug where colors with R, G, or B values under 16 could import as black"
   - Example: "Treats noteOn events with velocity 0 as noteOff events: Some DAWs (including Reaper) use this convention"