Apply suggestions from code review

Co-authored-by: Techassi <git@techassi.dev>

Author: sbernauer

.github/ISSUE_TEMPLATE/pre-release-from-scratch-testing.md

@@ -103,10 +103,12 @@ These instructions are for deploying and completing the nightly demo from scratc
 > Be sure to select the _nightly_ docs version on <https://docs.stackable.tech/home/nightly/demos/>.
 
 ```shell
-# Install demo (stable operators) for the nightly release.
-# For stacks use "stackablectl stack install" instead
+# For demo testing, install demo (stable operators) for the nightly release.
 stackablectl demo install <DEMO_NAME> --release dev
 
+# For stack testing, install stack via
+stackablectl stack install <STACK_NAME> --release dev
+
 # --- IMPORTANT ---
 # Run through the nightly demo instructions (refer to the list above).
 ```

.github/ISSUE_TEMPLATE/pre-release-upgrade-testing.md

@@ -105,10 +105,12 @@ the operators and CRDS.
 > Be sure to select the _stable_ docs version on <https://docs.stackable.tech/home/stable/demos/>.
 
 ```shell
-# Install demo (stable operators) for the stable release (OO.M).
-# For stacks use "stackablectl stack install" instead
+# For demo testing, , install demo (stable operators) for the stable release (OO.M).
 stackablectl demo install <DEMO_NAME>
 
+# For stack testing, install stack via
+stackablectl stack install <STACK_NAME> 
+
 # --- IMPORTANT ---
 # Run through the stable demo instructions (refer to the list above).
 

.github/ISSUE_TEMPLATE/release-from-scratch-testing.md

@@ -105,10 +105,12 @@ These instructions are for deploying and completing the YY.M.X demo from scratch
 > Be sure to select the _nightly_ docs version on <https://docs.stackable.tech/home/nightly/demos/>.
 
 ```shell
-# Install demo (stable operators) for the nightly release.
-# For stacks use "stackablectl stack install" instead
+# For demo testing, install demo (stable operators) for the YY.M.X release.
 stackablectl demo install <DEMO_NAME>
 
+# For stack testing, install stack via
+stackablectl stack install <STACK_NAME> 
+
 # --- IMPORTANT ---
 # Run through the nightly demo instructions (refer to the list above).
 ```