Update Keychron boards - Part 4

[adophoxia]

Description

This is Part 4 of a 5-part series of PRs to updating the entire Keychron lineup to current QMK standards. Since doing 1 PR to update 25 keyboards is unmanageable, doing them in batches would help make it tolerable. (What is changed can be shown in Part 1 below.)

• Update Keychron boards - Part 1 (redo) #21406

Additional changes:

• Update readme.md to include Imgur links for each board and to add separate make and flash commands for each board variant.

Keyboard-specific

• V3
  • Encoder variants has half of the column pins after A5 set as null while the non-encoder variants have actual pins defined for the colums. Therefore, the matrix_pins must be specified in each variant's info.json seperately.

Part 1 involves updating the following KC boards:

• S1
• V1
• V2
• V3
• V4

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[adophoxia]

Build errors for only the spidey3 keymaps. Everything else is fine.

[github-actions]

Thank you for your contribution!
This pull request has been automatically marked as stale because it has not had activity in the last 45 days. It will be closed in 30 days if no further activity occurs. Please feel free to give a status update now, or re-open when it's ready.
For maintainers: Please label with bug, awaiting review, breaking_change, in progress, or on hold to prevent the issue from being re-flagged.

[github-actions]

Thank you for your contribution!
This pull request has been automatically marked as stale because it has not had activity in the last 45 days. It will be closed in 30 days if no further activity occurs. Please feel free to give a status update now, or re-open when it's ready.
For maintainers: Please label with bug, awaiting review, breaking_change, in progress, or on hold to prevent the issue from being re-flagged.

[github-actions]

Thank you for your contribution!
This pull request has been automatically closed because it has not had activity in the last 30 days. Please feel free to give a status update now, ping for review, or re-open when it's ready.
// [stale-action-closed]