(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/getting-started/installation.md

@@ -0,0 +1,29 @@
+# Installation
+
+This section will guide you through the installation process of PyFlowery.
+
+## pip
+
+You can use pip to install PyFlowery.  
+The command to use differs slightly depending on what operating system you use.
+
+On Windows:
+
+``` prolog title="Command Prompt"
+py -m pip install pyflowery
+```
+
+On macOS and Linux:
+
+``` prolog title="Bash"
+python3 -m pip install pyflowery
+```
+
+## Poetry
+
+You can also use [Poetry](https://python-poetry.org/) to store your dependencies.  
+Use the following command to install PyFlowery:
+
+``` prolog title="Command Prompt / Shell"
+poetry add pyflowery
+```