Merge remote-tracking branch 'origin/5.3.1-develop' into fixing-tests

# Conflicts:
#	CHANGELOG.md
#	README.md
#	build.gradle
#	resources/META-INF/plugin.xml

Author: VitaliyBoyko

CHANGELOG.md

@@ -6,6 +6,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0).
 
 ## 5.4.0
 
+## 5.3.1
+
+### Fixed
+
+- Custom theme couldn't be detected [#2348](https://github.com/magento/magento2-phpstorm-plugin/pull/2348)
+
 ## 5.3.0
 
 ### Added