add NREL_DEVELOPER_EMAIL to env, docs

Author: zolanaj

docs/src/index.md

@@ -10,13 +10,16 @@ REopt evaluations for all system types except GHP (see below) can be performed u
 (active_env) pkg> add REopt JuMP HiGHS
 ```
 
-### Add NREL developer API key for PV and Wind
+### Add NREL developer API key for PV, CST, and Wind
 If you don't have an NREL developer network API key, [sign up here on https://developer.nrel.gov to get one (free)](https://developer.nrel.gov/signup); this is required to load PV and Wind resource profiles from PVWatts and the Wind Toolkit APIs from within REopt.jl.
 Assign your API key to the expected environment variable:
 ```julia
 ENV["NREL_DEVELOPER_API_KEY"]="your API key"
 ```
-before running PV or Wind scenarios.
+before running PV or Wind scenarios, and also assign your email to the expected environment variable as well before running CST scenarios: 
+```julia
+ENV["NREL_DEVELOPER_EMAIL"]="your contact email"
+```
 
 ### Additional package loading for GHP
 GHP evaluations must load in the [`GhpGhx.jl`](https://github.com/NREL/GhpGhx.jl) package separately because it has a more [restrictive license](https://github.com/NREL/GhpGhx.jl/blob/main/LICENSE.md) and is not a registered Julia package.

test/.env

@@ -1,2 +1,3 @@
 NREL_DEVELOPER_API_KEY="X3Fd4msuCdRGpgelMSjr8FYXfgdjWSuHHMdZE8Ta"
-URDB_API_KEY="2qt5uihpKXdywTj3uMIhBewxY9K4eNjpRje1JUPL"
+URDB_API_KEY="2qt5uihpKXdywTj3uMIhBewxY9K4eNjpRje1JUPL"
+NREL_DEVELOPER_EMAIL="reopt@nrel.gov"