chore: Move common_issues.md to docs/sdk_developers for unified documentation (#516) (#644)

Signed-off-by: Rishabh Ranjan Singh <rishabhrsingh19@gmail.com>

Author: Rishabh1925

CHANGELOG.md

@@ -15,6 +15,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 ### Changed
 
 - chore: fix type hint for TokenCancelAirdropTransaction pending_airdrops parameter
+- chore: Moved documentation file `common_issues.md` from `examples/sdk_developers/` to `docs/sdk_developers/` for unified documentation management (#516).
 
 ### Fixed