[PyPI] Packaging for PyPI distribution (#140)

docs/source/getting_started/installation.rst

@@ -32,7 +32,7 @@ You can install CacheFlow using pip:
     $ conda activate myenv
 
     $ # Install CacheFlow.
-    $ pip install cacheflow
+    $ pip install cacheflow  # This may take 5-10 minutes.
 
 
 .. _build_from_source:
@@ -46,5 +46,4 @@ You can also build and install CacheFlow from source.
 
     $ git clone https://github.com/WoosukKwon/cacheflow.git
     $ cd cacheflow
-    $ pip install -r requirements.txt
     $ pip install -e .  # This may take 5-10 minutes.