Small changes to documents in the root directory

- brought over the previous LICENSE from branch v18.2.1
- brought over the previous README from v18 and updated for references to "NSF Unidata" and other modern updates
- renamed awips_install-v20.sh to the regular name of awips_install.sh
- brought over the environment.yml file from the branch v18.2.1

LICENSE

@@ -0,0 +1,13 @@
+Copyright 2021 University Corporation for Atmospheric Research
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

README.md

@@ -0,0 +1,45 @@
+# Unidata AWIPS
+
+[https://www.unidata.ucar.edu/software/awips/](https://www.unidata.ucar.edu/software/awips/)
+
+[![GitHub release](https://img.shields.io/github/release/Unidata/awips2/all.svg)]() 
+
+The Advanced Weather Interactive Processing System (AWIPS) is a meteorological software package.  It is used for decoding, displaying, and analyzing data, and was originally developed for the National Weather Service (NWS) by Raytheon. There is a program at UCAR called the NSF Unidata Program Center (UCP) which develops and supports a modified non-operational version of AWIPS for use in research and education by academic institutions.  This is released as open source software, free to download and use.
+
+AWIPS takes a unified approach to data ingest, where most data ingested into the system comes through the LDM client pulling data feeds from the [NSF Unidata IDD](https://www.unidata.ucar.edu/projects/#idd). Various raw data and product files (netCDF, grib, BUFR, ASCII text, gini, AREA) are decoded and stored as HDF5 files and Postgres database entries by [EDEX](docs/install/install-edex), which serves products and data over http.
+
+Unidata supports two data visualization frameworks: [CAVE](docs/install/install-cave) (an Eclipse-built Java application which runs on Linux, Mac, and Windows), and [python-awips](docs/python/overview) (a programatic API written as a python package).
+
+> **Note**: Our version of CAVE is a **non-operational** version.  It does not support some features of NWS AWIPS.  Warnings and alerts cannot be issued from our builds of CAVE.  Additional functionality may not be available as well.
+
+
+![CAVE](https://www.unidata.ucar.edu/software/awips2/images/Unidata_AWIPS2_CAVE.png)
+
+---
+
+## License
+
+NSF Unidata AWIPS source code and binaries (RPMs) are considered to be in the public domain, meaning there are no restrictions on any download, modification, or distribution in any form (original or modified).  NSF Unidata AWIPS license information can be found [here](./LICENSE).
+
+---
+
+## AWIPS Data in the Cloud
+
+NSF Unidata and XSEDE Jetstream have partnered to offer an EDEX data server in the cloud, open to the community.  Select the server in the Connectivity Preferences dialog, or enter **`edex-cloud.unidata.ucar.edu`** (without *http://* before, or *:9581/services* after).
+
+![EDEX in the cloud](docs/images/connectWindow.png)
+
+
+# Documentation - http://unidata.github.io/awips2/
+
+Popular Pages:
+
+* [NSF Unidata AWIPS User Manual](http://unidata.github.io/awips2/)
+* [How to Install CAVE](http://unidata.github.io/awips2/install/install-cave)
+* [How to Install EDEX](http://unidata.github.io/awips2/install/install-edex)
+* [Common Problems with AWIPS](http://unidata.github.io/awips2/appendix/common-problems)
+* [Educational Resources](http://unidata.github.io/awips2/appendix/educational-resources)
+* [python-awips Data Access Framework](http://unidata.github.io/python-awips/)
+* [awips2-users Mailing List Archives](https://www.unidata.ucar.edu/mailing_lists/archives/awips2-users/)
+
+	* [(click to subscribe)](mailto:awips2-users-join@unidata.ucar.edu)

environment.yml

@@ -0,0 +1,11 @@
+# Create full conda environment for development, including some useful tools
+name: awips-docs
+channels:
+  - conda-forge
+dependencies:
+  - python=3.8
+  - pip
+  - pip:
+    - mkdocs
+    - mkdocs-unidata
+    - fontawesome_markdown