Improve dialog

This version does not comprise any functinal differences compared to the previous version. The only changes are:

• The dialog presented to the user has been improved.
• Instructions on how to use the plugin are now provided in the Readme file: https://github.com/hansenjn/ExtractSharpestPlane_JNH/blob/main/README.md

Initial Release

v0.0.1

Corrections