fix: restore TTS.__version__ attribute

This is used by the TTS/bin/collect_env_info.py script with which users print
version information for bug reports. We restore the TTS.__version__ attribute so
that old versions of the script still work.

TTS/__init__.py

@@ -0,0 +1,3 @@
+import importlib.metadata
+
+__version__ = importlib.metadata.version("coqui-tts")

docs/source/conf.py

@@ -20,7 +20,7 @@ sys.path.insert(0, os.path.abspath("../.."))
 autodoc_mock_imports = ["soundfile"]
 
 # -- Project information -----------------------------------------------------
-project = "TTS"
+project = "coqui-tts"
 copyright = "2021 Coqui GmbH, 2020 TTS authors"
 author = "Coqui GmbH"