add gitignore to example project

Author: yanboyko

ExampleApp/.gitignore

@@ -0,0 +1,33 @@
+*.DS_Store
+.DS_Store
+*.generated.swift
+
+## Build generated
+build/
+DerivedData/
+xcuserdata/
+xcshareddata/
+/.swiftpm
+*.xcuserstate
+
+## Various settings
+*.pbxuser
+!default.pbxuser
+*.mode1v3
+!default.mode1v3
+*.mode2v3
+!default.mode2v3
+*.perspectivev3
+!default.perspectivev3
+
+## Other
+*.moved-aside
+*.xccheckout
+*.xcscmblueprint
+
+# Swift Package Manager
+.build/
+Package.resolved*
+
+# SwiftLint
+lintOutput.json