[doc] update conda to usage link in installation (#15761)

Signed-off-by: reidliu41 <reid201711@gmail.com>
Co-authored-by: reidliu41 <reid201711@gmail.com>

docs/source/getting_started/installation/python_env_setup.inc.md

-You can create a new Python environment using `conda`:
+You can create a new Python environment using [conda](https://docs.conda.io/projects/conda/en/stable/user-guide/getting-started.html):
 
 ```console
 # (Recommended) Create a new conda environment.