The root README described only dbmole and never mentioned esmole, even
though the repo now ships both servers. Rework it into a monorepo landing
page: a package table, a shared `.mcp.json` quick start, and the connection
model both servers inherit from @dbmole/core.
Move the dbmole-specific reference into packages/dbmole-mcp/README.md so the
package has its own doc on npm, mirroring esmole. Fix the stale Docker build
command there: the Dockerfile moved under packages/dbmole-mcp, so the build
now needs -f and the repo root as context. This also resolves esmole's
README link to ../dbmole-mcp/README.md, which pointed at a missing file.