README: add three more status buttons

[jbampton]

The 3 new buttons added are:

• Good first issue
• Read the Docs build status
• CloudStack website status

Description

This PR enhances the visibility of the project by adding helpful links.

The good first issue button is very helpful it helps onboard new GitHubbers quicker and directs them to easier issues.

Example here:

https://github.com/jbampton/cloudstack/tree/add-readme-badges?tab=readme-ov-file#apache-cloudstack

And seen in this image:

Types of changes

• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] Enhancement (improves an existing feature and functionality)
• [ ] Cleanup (Code refactoring and cleanup, that may add test cases)
• [ ] build/CI
• [ ] test (unit or integration test code)

Feature/Enhancement Scale or Bug Severity

Feature/Enhancement Scale

• [ ] Major
• [ ] Minor

Bug Severity

• [ ] BLOCKER
• [ ] Critical
• [ ] Major
• [ ] Minor
• [ ] Trivial

Screenshots (if appropriate):

How Has This Been Tested?

Visually and with a screenshot as it is only editing the README

How did you try to break this feature and the system with this change?

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 17.50%. Comparing base (bb5da0e) to head (607b3cb).

Additional details and impacted files

@@            Coverage Diff            @@
##               main   #11650   +/-   ##
=========================================
  Coverage     17.50%   17.50%           
- Complexity    15567    15568    +1     
=========================================
  Files          5914     5914           
  Lines        529642   529642           
  Branches      64702    64702           
=========================================
+ Hits          92691    92692    +1     
+ Misses       426500   426499    -1     
  Partials      10451    10451           

Flag	Coverage Δ
uitests	3.58% <ø> (ø)
unittests	18.56% <ø> (+<0.01%)	:arrow_up:

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