Cean sandbox (#1815)

* Add dynamic key values to secrets.properties in idx template

Update idx template to read local.defaults.properties and
generate key entries in secrets.properties file using the
user's provided API key.

* Fix incorrect variable for key

Update key to be keyVar when writing to secrets.properties

* fix: remove newline from comment

Comment contained newline that made the template read the
filename as a command.

open-in-idx-template/idx-template.nix

@@ -16,9 +16,8 @@
 
     # Create a secrets.properties file in the repo
     touch $WS_NAME/secrets.properties
-    
-    # Create a secrets.properties variable for each key type in the
-      local.defaults.properties file
+
+    # Create a secrets.properties variable for each key type in local.defaults.properties
     
     while IFS= read -r line || [[ -n "$line" ]]; do
       # Check that an "=" exists in the line
@@ -35,4 +34,4 @@
 
     mv "$WS_NAME" "$out"
   '';
-}
+}