Simplify programmatic access of whispr

Description

• This release simplified programmatic access of code whispr utilities
• execute_command will not fail silently if there is a problem with subprocess.
• Add programmatic sue guide in usage-guides.

What's Changed

• Update issue templates by @narenaryan in #14
• test(ISSUE-4): Improve code coverage by @narenaryan in #15
• docs: create programmatic-access guide by @narenaryan in #16
• release: bump up version to v0.3.0 by @narenaryan in #17

Full Changelog: v0.2.0...v0.3.0