docs: add NIP-62 to supported features list

[vikashsiwach]

Description

Adds NIP-62 (Request to Vanish) to the supported features list.

Motivation and Context

NIP-62 has been implemented and covered by integration tests.

Types of changes

• Non-functional change (docs, style, minor refactor)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my code changes.
• I added a changeset, or this is docs-only and I added an empty changeset.
• All new and existing tests passed.

[coveralls]

coverage: 73.323%. remained the same — vikashsiwach:docs/add-nip62-feature into cameri:main

[CKodidela]

@vikashsiwach can you add changeset?

[CKodidela]

@cameri