Update inlineCollections list in ElementDocumentProcessor

[RachamimYaakobov]

Description:

Added "Bold", "Italic", "Underline" types to the inlineCollections list

Checklist:

• I have commented my code, particularly in hard-to-understand areas
• 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
• I have tested my changes by running the extension in VS2017
• I have tested my changes by running the extension in VS2019
• I have tested my changes by running the extension in VS2022
• If changes to the documentation are needed, I have noted this in the description above

[NicoVermeir]

@RachamimYaakobov so sorry for letting this go stale. Can you tell me which problem you're solving with your PR?
Thank you for contributing!