Refactor Config to extract DefaultConfig and RepositoryConfig subclasses

This refactors `Config` to extract two new subclasses, `DefaultConfig` and `RepositoryConfig`, which are used to logically and semantically indicate the purpose of a given `Config` object. This also substantially improves the documentation for the existing `Config` class.

Author: beamerblvd

docs/config.rst

@@ -2,22 +2,31 @@
 Configuration files
 **********************************************************************
 
-.. autoclass:: pygit2.Repository
-   :members: config
-   :noindex:
+.. autoclass:: pygit2.repository.BaseRepository
+   :members: config, config_snapshot
 
 
-The Config type
+The Config types
 ================
 
 .. autoclass:: pygit2.Config
    :members:
    :undoc-members:
-   :special-members: __contains__, __delitem__, __getitem__, __iter__, __setitem__
+   :special-members: __contains__, __delitem__, __getitem__, __init__, __iter__, __setitem__
+
+.. autoclass:: pygit2.DefaultConfig
+   :members: add_file, snapshot
+   :undoc-members:
+   :special-members: __init__
+
+.. autoclass:: pygit2.RepositoryConfig
+   :members: add_file, snapshot
+   :undoc-members:
+   :special-members: __init__
 
 
 The ConfigEntry type
 ====================
 
 .. autoclass:: pygit2.config.ConfigEntry
-   :members: name, value, level
+   :members: level, name, raw_level, raw_name, raw_value, value, __eq__, __hash__

pygit2/__init__.py

@@ -301,7 +301,11 @@
     git_fetch_options,
     git_proxy_options,
 )
-from .config import Config
+from .config import (
+    Config,
+    DefaultConfig,
+    RepositoryConfig,
+)
 from .credentials import *
 from .errors import (
     AlreadyExistsError,
@@ -606,6 +610,7 @@ def filter_unregister(name: str) -> None:
     'Branch',
     'CertificateError',
     'Commit',
+    'DefaultConfig',
     'Diff',
     'DiffDelta',
     'DiffFile',
@@ -941,6 +946,7 @@ def filter_unregister(name: str) -> None:
     'Remote',
     'repository',
     'Repository',
+    'RepositoryConfig',
     'branches',
     'references',
     'settings',