Rearrange README content

[tp832944]

closes: #501

PR Type

• Documentation content changes

Description

Move testing section to CONTRIBUTING.md.

Merge examples and main READMEs.

Improve installation instructions.

Other minor improvements.

How Has This Been Tested?

Read it.

Does this PR introduce a breaking change?

No

Screenshots

Checklist before requesting a review

• I have made sure that my PR is not a duplicate.
• My code follows the style guidelines of this project.
• I have commented my code, particularly in hard-to-understand areas.
• I have performed a self-review of my code.
• 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.
• Any dependent changes have been merged and published in downstream modules.

[gw265981]

The README and CONTRIBUTING look great, happy to merge.