Fix included JetBrains files.

.gitignore

@@ -412,8 +412,7 @@ test-results/
 ### GPG template
 secring.*
 
-### JetBrains template
-# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and WebStorm
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio, WebStorm and Rider
 # Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
 
 # User-specific stuff
@@ -423,6 +422,9 @@ secring.*
 .idea/**/dictionaries
 .idea/**/shelf
 
+# Generated files
+.idea/**/contentModel.xml
+
 # Sensitive or high-churn files
 .idea/**/dataSources/
 .idea/**/dataSources.ids
@@ -440,9 +442,14 @@ secring.*
 # When using Gradle or Maven with auto-import, you should exclude module files,
 # since they will be recreated, and may cause churn.  Uncomment if using
 # auto-import.
+# .idea/artifacts
+# .idea/compiler.xml
+# .idea/jarRepositories.xml
 # .idea/modules.xml
 # .idea/*.iml
 # .idea/modules
+# *.iml
+# *.ipr
 
 # CMake
 cmake-build-*/
@@ -473,6 +480,10 @@ fabric.properties
 
 # Editor-based Rest Client
 .idea/httpRequests
+
+# Android studio 3.1+ serialized cache file
+.idea/caches/build_file_checksums.ser
+
 ### CMake template
 CMakeCache.txt
 CMakeFiles