Fix installation

[william-hutchison]

A few bug fixes:

• Fix the Azimuth package remote address (this bug means HPCell cannot currently install).
• Fix incorrectly attributed function imports.
• Fix a typo in the README.

[william-hutchison]

A few more bug fixes to address all R CMD Errors:

• Add a missing remote.
• Add multiple packages imported from in NAMESPACE to DESCRIPTION imports.
• Updated an example with :: notation.
• Removed inheritance of examples for test_differential_abundance from tidybulk as they were failing. I think they could be fixed in tidybulk by declaring all imports with :: notation in relevant examples.

GIthub actions are showing failure because of R CMD Warnings. Fixing these is probably beyond the scope of this PR. I will also attempt to solve the bug I encountered in SCTransform in a separate PR.