fix: Update linkspector to check links to headings with inline bold, italic, code, link, and image elements

[gaurav-nelson]

Description

Updated linkspector to check links to headings with inline bold, italic, code, link, and image elements. The getText function now correctly parses parts of heading to convert into slug.

Fixes #72

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes