[Build] Add documentation for some useful properties in gradle.properties

gradle.properties

@@ -20,9 +20,6 @@ kotlin.build.publishing.attempts=20
 # Enable when https://youtrack.jetbrains.com/issue/KT-47520 will be fixed
 kotlin.jvm.target.validation.mode=ignore
 
-#jpsBuild=true
-#cidrPluginsEnabled=true
-#idea.fir.plugin=true
 #attachedIntellijVersion=203 (or any other platform version)
 
 ## Used for compare gradle and jps build
@@ -43,3 +40,22 @@ kotlin.native.enabled=false
 kotlin.native.home=kotlin-native/dist
 
 org.gradle.vfs.watch=true
+
+# Enable JPS build
+#jpsBuild=true
+
+# Enable compilation of project using FIR compiler
+#kotlin.build.useFir=true
+
+# Enable overriding JDK 6 and JDK 7 with JDK 8 in java toolchains
+# This flag is required if you don't have JDK 6 or JDK 7 manually installed
+#kotlin.build.isObsoleteJdkOverrideEnabled=true
+
+# Disable -Werror compiler flag
+#kotlin.build.disable.werror=true
+
+# Enable bootstrap from local build of compiler (build from ./gradlew publish)
+#bootstrap.local=true
+# By default bootstrap compiler is located in ./build/repo directory
+# If it differs from default use next flag:
+#bootstrap.local.path=/path/to/repo