feat(developer): kmc-convert: create a document for kmc-convert keylayout-kmn 😎

[SabineSIL]

This is to create a documentation on kmc-convert keylayout-kmn,

The document provides information about

• structure of a .keylayout file
• rule types C0-C3 used for reading data
• the Array of Rule to store data
• reviewing of rules (compare, add warnings, omit duplicate lines)

@keymanapp-test-bot skip

[keymanapp-test-bot]

User Test Results

Test specification and instructions

User tests are not required

Test Artifacts

• Developer
  • Keyman Developer - build : all tests passed (no artifacts on BuildLevel "build")
  • Compiler Regression Tests - build : all tests passed (no artifacts on BuildLevel "build")
  • Keyman Developer (old PRs) - build : all tests passed (no artifacts on BuildLevel "build")
  • kmcomp.zip - build : all tests passed (no artifacts on BuildLevel "build")
  • kmcomp.zip (old PRs) - build : all tests passed (no artifacts on BuildLevel "build")
• Keyboards
  • Test Keyboards - build : all tests passed (no artifacts on BuildLevel "build")