point to readthedocs for installation

README.md

@@ -1,82 +1,6 @@
-Installation, setup and development rules for the CASA Next Generation Infrastructure  
+All documentation can be found here: [https://cngi-prototype.readthedocs.io](https://cngi-prototype.readthedocs.io/)
 
-# Installation
-Conversion functions depend on casatools from [CASA 6](https://open-bitbucket.nrao.edu/projects/CASA/repos/casa6/browse) which is currently compatible with Python 3.6 only.  CASA 6 also requires FORTRAN libraries be installed in the OS.
-These are not included in the dependency list so that the rest of CNGI functionality may be used without these constraints.
+Installation section is here: [https://cngi-prototype.readthedocs.io/en/latest/introduction.html#Installation](https://cngi-prototype.readthedocs.io/en/latest/introduction.html#Installation)
 
-In the future, the conversion module may be moved outside of the CNGI package and distributed separately.
 
-## Pip Installation
-
-```sh
-python3 -m venv cngi
-source cngi/bin/activate
-#(maybe) sudo apt-get install libgfortran3
-pip install --index-url https://casa-pip.nrao.edu/repository/pypi-casa-release/simple casatools==6.0.0.27
-pip install cngi-prototype
-```
-
-## Conda Installation
-
-```sh
-conda create -n cngi python=3.6
-conda activate cngi
-#(maybe) sudo apt-get install libgfortran3
-pip install --index-url https://casa-pip.nrao.edu/repository/pypi-casa-release/simple casatools==6.0.0.27
-pip install cngi-prototype
-```
-
-
-## Installation from Source
-
-```sh
-git clone https://github.com/casangi/cngi_prototype.git
-cd cngi_prototype
-python3 -m venv venv
-source venv/bin/activate
-pip install wheel
-pip install -r requirements.txt
-python setup.py install --root=.
-```
-
-## Configure dask.distributed
-To avoid thread collisions, when using the Dask.distributed Client, set the following environment variables.
-
-```sh
-export OMP_NUM_THREADS=1 
-export MKL_NUM_THREADS=1
-export OPENBLAS_NUM_THREADS=1 
-```
-
-##  Building Documentation from Source
-Follow steps to install cngi from source. Then navigate to the docs folder and execute the following:
-
-```sh
-sphinx-build -b html . ./build
-```
-View the documentation in your browser by navigating to:
-
- ```sh
-file:///path/to/cngi/cngi_prototype/docs/build/index.html
-```
-
-
-# Usage
-You can import things several different ways.  For example:
-```python
->>> from cngi import dio
->>> xds = dio.read_image(...)
-```
-or
-```python
->>> from cngi.dio import read_image
->>> xds = read_image(...)
-```
-or
-```python
->>> import cngi.dio as cdio
->>> xds = cdio.read_image(...)
-```
-
-Throughout the documentation we use the variable name `xds` to refer to Xarray DataSets.  
-`xda` may be used to refer to Xarray DataArrays.  This is a "loose" convention only. 
+Note, throughout the documentation we use the variable name `xds` to refer to Xarray DataSets, the core data structure on which everything is built. It is important to distinguish objects that are xarray/dask based from other standard Python objects.