doc: imagekit and development documentations added

Author: mrasif

DEVELOPMENT.md

@@ -0,0 +1,21 @@
+# Development Guide
+
+
+**1. To modify version open `imagekit-sdk/build.gradle` and change value of `version`.**
+
+**2. Run test cases**
+```shell
+./gradlew imagekit-sdk:test
+```
+
+**3. Clean cache of SDK**
+```shell
+./gradlew imagekit-sdk:clean
+```
+
+**4. Build SDK jar**
+```shell script
+./gradlew imagekit-sdk:build
+```
+Then you will find `jar` inside `imagekit-sdk/build/libs/` with specific version name. Then you can share `jar` or upload `jar` to any java dependency repository.
+