(2.0.0) woohoo, first major version bump!

bunch of stuff this update, including a full documentation site (still a WIP)
there is now a cache created whenever an instance of `FloweryAPI` is instantiated, so you don't have to query the api and iterate through the api response to retrieve a single voice anymore!
function names have also been changed with this update, hence the major version bump. `get_tts()`, `get_voices()`, and `get_voice()` have been renamed to `fetch_tts()`, `fetch_voices()`, and `fetch_voice()` respectively. `get_voices()` still exists, but with different functionality (that method retrieves voices from the internal cache instead of querying the flowery api)

!BREAKING

docs/ref/exceptions.md

@@ -0,0 +1,3 @@
+# Exceptions
+
+::: pyflowery.exceptions