Fix stale BLAST documentation after PR #8 #11

Summary

Update docs/api/blast.rst to match the BLAST refactor merged in PR #8 and restore the documentation build.

Required changes

• Remove the RemoteBlastSearcher autodoc block because the class was deleted from src/lverage/blast.py.
• Remove or rewrite the documentation describing the remote BLAST adapter, -remote execution, NCBI E-utilities, and remote-search parallelization guidance.
• Update the wording that refers to “both adapters” so it describes only LocalBlastSearcher.
• Preserve the relevant local BLAST prerequisites and usage documentation.

Verification

Build the documentation successfully with the repository’s documentation build command and confirm that no references to RemoteBlastSearcher remain in the generated documentation sources.