Cleanup .gitignore

Remove committed .idea directory
diff --git a/.gitignore b/.gitignore
index fd4bf9d..714afaf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,4 @@
+# https://dart.dev/guides/libraries/private-files
 .packages
-.idea/
-.pub/
 .dart_tool/
-build/
-doc/api/
 pubspec.lock
diff --git a/.idea/modules.xml b/.idea/modules.xml
deleted file mode 100644
index 884b2a8..0000000
--- a/.idea/modules.xml
+++ /dev/null
@@ -1,8 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="ProjectModuleManager">
-    <modules>
-      <module fileurl="file://$PROJECT_DIR$/.idea/usage.iml" filepath="$PROJECT_DIR$/.idea/usage.iml" />
-    </modules>
-  </component>
-</project>
\ No newline at end of file
diff --git a/.idea/usage.iml b/.idea/usage.iml
deleted file mode 100644
index 2c3b394..0000000
--- a/.idea/usage.iml
+++ /dev/null
@@ -1,15 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
-    <exclude-output />
-    <content url="file://$MODULE_DIR$">
-      <excludeFolder url="file://$MODULE_DIR$/.dart_tool" />
-      <excludeFolder url="file://$MODULE_DIR$/.pub" />
-      <excludeFolder url="file://$MODULE_DIR$/build" />
-    </content>
-    <orderEntry type="inheritedJdk" />
-    <orderEntry type="sourceFolder" forTests="false" />
-    <orderEntry type="library" name="Dart Packages" level="project" />
-    <orderEntry type="library" name="Dart SDK" level="project" />
-  </component>
-</module>
\ No newline at end of file