refactor(devtools): remove the standalone demo (angular#62455)

The default demo is already standalone

PR Close angular#62455

Author: JeanMeche

.aspect/rules/external_repository_action_cache/npm_translate_lock_MzA5NzUwNzMx

@@ -8,7 +8,7 @@ adev/shared-docs/package.json=450629456
 adev/shared-docs/pipeline/api-gen/package.json=939673974
 integration/package.json=-239561259
 modules/package.json=-2081919225
-package.json=1306517978
+package.json=-1401411541
 packages/animations/package.json=-678724831
 packages/benchpress/package.json=-1908328724
 packages/common/package.json=1729763064

devtools/README.md

@@ -46,12 +46,6 @@ To run the extension in development mode run:
 yarn devtools:devserver
 ```
 
-You can also run a standalone version of the demo app with:
-
-```shell
-yarn devtools:devserver:demo-standalone
-```
-
 This would start a development server that you can access on <http://localhost:4200>. In development, Angular DevTools
 uses a "development shell." This is different from "chrome shell" in a way, that it runs the user's app in an iframe.
 DevTools then communicate with the user's app via message passing.