`FullRepoManager` document has mild render error

[MapleCCC]

The current document of FullRepoManager is as shown in the following picture:

It can be seen that the format is mildly broken.

Let's look at the docstring in the source code of FullRepoManager:

https://github.com/Instagram/LibCST/blob/977504f10407b3d94bbe45157f9286709dd74754/libcst/metadata/full_repo_manager.py#L25-L36

Turn out that the error originates from how we violate the syntax rules of the field list markup element of reStructuredText. The specification of field list states that a multi-line field body must be indented relative to the field marker. Therefore, we can fix the error with the following changes:

        Given project root directory with pyre and watchman setup, :class:`~libcst.metadata.FullRepoManager`
        handles the inter process communication to read the required full repository cache data for
        metadata provider like :class:`~libcst.metadata.TypeInferenceProvider`.
        :param paths: a collection of paths to access full repository data.
        :param providers: a collection of metadata provider classes require accessing full repository data, currently supports
-       :class:`~libcst.metadata.TypeInferenceProvider` and
-       :class:`~libcst.metadata.FullyQualifiedNameProvider`.
+           :class:`~libcst.metadata.TypeInferenceProvider` and
+           :class:`~libcst.metadata.FullyQualifiedNameProvider`.
        :param timeout: number of seconds. Raises `TimeoutExpired <https://docs.python.org/3/library/subprocess.html#subprocess.TimeoutExpired>`_
            when timeout.