Fix some incorrect sphinx markups in the docstrings

Fixed some markups so
[the api reference](https://gitpython.readthedocs.io/en/stable/reference.html)
is rendered correctly.

Author: Yuki Kobayashi

git/index/base.py

@@ -508,7 +508,7 @@ def iter_blobs(
 
         :param predicate:
             Function(t) returning ``True`` if tuple(stage, Blob) should be yielded by
-            the iterator. A default filter, the `~git.index.typ.BlobFilter`, allows you
+            the iterator. A default filter, the :class:`~git.index.typ.BlobFilter`, allows you
             to yield blobs only if they match a given list of paths.
         """
         for entry in self.entries.values():
@@ -770,7 +770,7 @@ def add(
             - path string
 
                 Strings denote a relative or absolute path into the repository pointing
-                to an existing file, e.g., ``CHANGES``, `lib/myfile.ext``,
+                to an existing file, e.g., ``CHANGES``, ``lib/myfile.ext``,
                 ``/home/gitrepo/lib/myfile.ext``.
 
                 Absolute paths must start with working tree directory of this index's
@@ -789,7 +789,7 @@ def add(
 
                 They are added at stage 0.
 
-            - :class:~`git.objects.blob.Blob` or
+            - :class:`~git.objects.blob.Blob` or
               :class:`~git.objects.submodule.base.Submodule` object
 
                 Blobs are added as they are assuming a valid mode is set.
@@ -815,7 +815,7 @@ def add(
 
             - :class:`~git.index.typ.BaseIndexEntry` or type
 
-                Handling equals the one of :class:~`git.objects.blob.Blob` objects, but
+                Handling equals the one of :class:`~git.objects.blob.Blob` objects, but
                 the stage may be explicitly set. Please note that Index Entries require
                 binary sha's.
 
@@ -998,7 +998,7 @@ def remove(
 
                 The path string may include globs, such as ``*.c``.
 
-            - :class:~`git.objects.blob.Blob` object
+            - :class:`~git.objects.blob.Blob` object
 
                 Only the path portion is used in this case.
 

git/objects/base.py

@@ -122,7 +122,7 @@ def new(cls, repo: "Repo", id: Union[str, "Reference"]) -> AnyGitObject:
         :return:
             New :class:`Object` instance of a type appropriate to the object type behind
             `id`. The id of the newly created object will be a binsha even though the
-            input id may have been a `~git.refs.reference.Reference` or rev-spec.
+            input id may have been a :class:`~git.refs.reference.Reference` or rev-spec.
 
         :param id:
             :class:`~git.refs.reference.Reference`, rev-spec, or hexsha.
@@ -218,7 +218,7 @@ class IndexObject(Object):
     """Base for all objects that can be part of the index file.
 
     The classes representing git object types that can be part of the index file are
-    :class:`~git.objects.tree.Tree and :class:`~git.objects.blob.Blob`. In addition,
+    :class:`~git.objects.tree.Tree` and :class:`~git.objects.blob.Blob`. In addition,
     :class:`~git.objects.submodule.base.Submodule`, which is not really a git object
     type but can be part of an index file, is also a subclass.
     """

git/objects/commit.py

@@ -289,7 +289,7 @@ def name_rev(self) -> str:
         """
         :return:
             String describing the commits hex sha based on the closest
-            `~git.refs.reference.Reference`.
+            :class:`~git.refs.reference.Reference`.
 
         :note:
             Mostly useful for UI purposes.
@@ -349,7 +349,7 @@ def iter_items(
         return cls._iter_from_process_or_stream(repo, proc)
 
     def iter_parents(self, paths: Union[PathLike, Sequence[PathLike]] = "", **kwargs: Any) -> Iterator["Commit"]:
-        R"""Iterate _all_ parents of this commit.
+        R"""Iterate *all* parents of this commit.
 
         :param paths:
             Optional path or list of paths limiting the :class:`Commit`\s to those that

git/repo/base.py

@@ -512,7 +512,7 @@ def create_submodule(self, *args: Any, **kwargs: Any) -> Submodule:
     def iter_submodules(self, *args: Any, **kwargs: Any) -> Iterator[Submodule]:
         """An iterator yielding Submodule instances.
 
-        See the `~git.objects.util.Traversable` interface for a description of `args`
+        See the :class:`~git.objects.util.Traversable` interface for a description of `args`
         and `kwargs`.
 
         :return: