Style Guide Updates from Ass1 and Ass2 feedback

[GHWang28]

QoL/misc additions

• Improved the example accordions - they are also by default closed now so it's easier to navigate through pages
  
• Added: "Below is our style guide for COMP6080 for writing X. For anything not mentioned here, refer to the Y."

Style Guide Changes

For HTML:

1. Spamming line break tags and  
2. No redundant attributes on tags
3. Avoid having multiple separate versions of a webpage component
4. Remove blocks of commented out code
5. Reworked alt tag - new examples on how to write good alt tags and added exception to not needing alt tag for images used for decoration (like for bullet points).

For CSS:

1. Overuse of !important
2. Avoid negative margins
3. Remove empty rulesets
4. Remove blocks of commented out code

For Javascript:

1. Reworked "Arrow functions over Regular functions" - removed the previous absolute need for arrow functions and added examples of when to use arrow functions and when to use regular functions.
2. Remove blocks of commented out code