Adding USGSCSM plugin to ISIS (#37)

* Docs on adding usgscsm plugin to isis

* Address feedback

* Include earlier versions

docs/how-to-guides/environment-setup-and-maintenance/adding-usgscsm-plugin-to-isis.md

@@ -0,0 +1,86 @@
+# Adding USGSCSM Plugin to ISIS
+
+???+ warning
+ Upcoming ISIS version 8.2 and future releases will include the USGSCSM library and does __not__ require a separate installation of the plugin.
+
+  ISIS versions 8.0LTS, 8.1, and earlier _require_ a separate installation of the USGSCSM plugin as shown below.
+
+## For users
+You can install the latest [USGSCSM](https://github.com/DOI-USGS/usgscsm) library via conda:
+
+```sh
+conda install conda-forge::usgscsm
+```
+
+## For developers
+
+???+ info
+ For USGSCSM versions 2.0 and above, the plugin is installed in `$CONDA_PREFIX/lib/csmplugins/` in an Anaconda environment.
+
+### Plugin setup
+If you are testing a new plugin or using older versions of USGSCSM/ISIS, you will need to update your `IsisPreferences` file located under the `ISIS3/isis` directory with the appropriate plugin path change. 
+
+For example, if your `CONDA_PREFIX` path is not the same are your `ISISROOT` path, you can add `"$CONDA_PREFIX/lib/csmplugins/"` to your `IsisPreferences` file under `Group = Plugins`:
+
+ ```
+ Group = Plugins
+ CSMDirectory = ("$CONDA_PREFIX/lib/csmplugins/", -
+ "$ISISROOT/lib/csmplugins/", -
+ "$ISISROOT/lib/isis/csm3.0.3/", -
+ "$ISISROOT/csmlibs/3.0.3/", -
+ "$HOME/.Isis/csm3.0.3/")
+ EndGroup
+ ```
+
+### Using your local build
+If you are working on USGSCSM, you can build a local conda package of USGSCSM and install that in your ISIS conda environment for testing. 
+
+#### Step 1: Create your local build
+First, activate your ISIS environment:
+```sh
+conda activate isis3
+```
+
+Second, go to your USGSCSM `/build` directory if it already exists and remove the CMakeCache.txt file:
+```sh
+cd <path-to-repos>/usgscsm/build
+rm -rf CMakeCache.txt
+```
+
+Third, run `cmake` while specifying the installation to be located in your currently activated conda environment's directory:
+```sh
+cmake .. -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX/
+```
+
+???+ note
+ Verify that you are in an activated conda environment: `echo $CONDA_PREFIX`
+
+Once the `cmake` command has finished running, build and install your local build:
+```sh
+make
+make install
+```
+
+#### Step 2: Install your local build
+First, make sure you are in the conda environment you installed the USGSCSM library to.
+
+Second, check if the USGSCSM package is conda installed. If so, remove it from your environment:
+
+```sh
+conda list usgscsm
+conda remove --force usgscsm
+```
+
+Third, remove the cmake cache from your ISIS build dir and [re-build ISIS](../isis-developer-guides/developing-isis3-with-cmake.md#building-isis3):
+
+```sh
+cd <path-to-repos>/ISIS3/build
+rm -rf CMakeCache.txt
+```
+
+#### Step 3: Test your local build
+Make sure your local build of USGSCSM is installed properly by running `csminit`:
+```sh
+which csminit
+csminit -h
+```

mkdocs.yml

@@ -50,6 +50,7 @@ nav:
  - Installing ISIS Via Anaconda: how-to-guides/environment-setup-and-maintenance/installing-isis-via-anaconda.md
  - Anaconda in a Network Environment: how-to-guides/environment-setup-and-maintenance/anaconda-in-a-network-environment.md
  - SPICE Kernel Updates in ISIS: how-to-guides/environment-setup-and-maintenance/spice-kernel-updates-in-isis.md
+ - Adding USGSCSM Plugin to ISIS: how-to-guides/environment-setup-and-maintenance/adding-usgscsm-plugin-to-isis.md
  - SPICE: 
  - Creating Spice Config Files in SpiceQL: how-to-guides/SPICE/creating-spice-config-files-in-spiceql.md
  - Image Processing: