message: chore: remove leftover readme
diff: @@ -257,24 +257,12 @@ you to install lean via elan. If the folder contains a `lean-toolchain` version
  otherwise it will install `leanprover/lean4:nightly`.
  You can override this default version by setting an `DEFAULT_LEAN_TOOLCHAIN` environment variable.
  -If elan is installed and there is a workspace override in place created by the `Select Toolchain`
  -command then this version takes precedence until you remove that override.
  -
  Otherwise, if there is a `lean-toolchain` (or `leanpkg.toml`) in the workspace folder or in a parent
  folder then it will use the version specified in the specified version.
  -Otherwise, if `elan toolchain list` shows there is a `(default)` toolchain it will use that version.
  -
  -Otherwise, it will prompt you to select a toolchain using the `Select Toolchain` command. If the
  -elan toolchain list is empty it will add `leanprover/lean4:nightly` to the list so that there is
  -always something to select.
  -
  Then with the selected version it runs `lean --version` to check if that version is installed yet.
  If this version is not yet installed `lean --version` will install it.
  -In the case of a workspace override the `+version` command line option is used on `lean --version`
  -and `lean --server` to ensure that the overridden version is used.
  -
  ## For VSCode extension developers
  See [Development](docs/dev.md).
  