docs: preserve entities names casing

[ilbertt]

Description

Preserve the entities (functions, variables, etc.) names casing in the pages and sidebar titles.

How Has This Been Tested?

Same tests should still pass.

Checklist:

• My changes follow the guidelines in CONTRIBUTING.md.
• The title of this PR complies with Conventional Commits.
• I have edited the CHANGELOG accordingly.
• I have made corresponding changes to the documentation.

[github-actions]

size-limit report 📦

Path	Size
@dfinity/agent	47.91 KB (0%)
@dfinity/assets	52.94 KB (0%)
@dfinity/auth-client	19.38 KB (0%)
@dfinity/candid	13.22 KB (0%)
@icp-sdk/core	91 B (0%)
@dfinity/identity	18.81 KB (0%)
@dfinity/identity-secp256k1	33.03 KB (0%)
@dfinity/principal	4.44 KB (0%)
@dfinity/use-auth-client	58.77 KB (0%)