chore(frontend): update IntelliJ IDEA configuration

Enable Telepresence support by creating two IntelliJ IDEA run
configurations:

- backend (telepresence): runs the backend, assuming that a Telepresence
  intercept has been created, like so:
      telepresence intercept greenstar-backend \
                             --port 8000:http \
                             --env-file ./backend/intercept.env
- frontend (telepresence): runs the frontend, assuming that a
  Telepresence intercept has been created, like so:
      telepresence intercept greenstar-frontend \
                             --port 8080:http \
                             --env-file ./frontend/intercept.env

[skip ci]

e2e.iml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$/e2e" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>