Add function to get a submission

I shouldn't have to use the Submission class to do anything outside of the library.

FAAPI/FAAPI.py

@@ -521,3 +521,11 @@ class FAAPI:
         :return: User that this instance is logged in as.
         """
         return self.get_user(self.username) if self.logged_in else None
+
+    def get_submission(self, id: int) -> Submission:
+        """
+        Gets a submission by its numeric ID.
+        :param id: Submission ID
+        :return: Submission
+        """
+        return Submission.new_or_cached(self, id)

setup.py

@@ -2,7 +2,7 @@ from setuptools import setup, find_packages
 
 setup(
     name='FAAPI',
-    version='0.3.1',
+    version='0.4.0',
     packages=find_packages(),
     url='https://tem.party/gitea/tom/FAAPI',
     license='WTFPL',