Add new macropad Sharkropad

[mawaeg]

Description

This PR adds a new macropad, Sharkropad, to the repository.

Types of Changes

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

[drashna]

All of this code should go into a sharkropad.c file instead, as the default keymap should be kept pristine.

Also, this effect list isn't .... exactly accurate. If effects are enabled/disabled, this list will drift. You may want something like this instead:
https://github.com/drashna/qmk_userspace/blob/65874ada48ff35d177c7a3cd10f2a6d5b9580e0c/users/drashna/rgb/rgb_matrix_stuff.c#L248-L307

This generates the list based on the enabled effects at compile time, and formats the strings to be a bit more pleasant. (it also keeps the last mode and associated string to skip the string generation if the mode hasn't changed).

[drashna]

No physical reset button on the pcb?

[waffle87]

Please remove executable file permission from these files:

.rw-r--r-- 809B jack 01 Mar 2025 12:56  config.h
.rwxr-xr-x 746B jack 01 Mar 2025 12:56  halconf.h
.rwxr-xr-x 4.7K jack 01 Mar 2025 12:56  keyboard.json
drwxr-xr-x 4.0K jack 01 Mar 2025 12:56  keymaps
.rwxr-xr-x 779B jack 01 Mar 2025 12:56  mcuconf.h
.rwxr-xr-x 931B jack 01 Mar 2025 12:56  readme.md

keymaps/default:
.rwxr-xr-x 3.3K jack 01 Mar 2025 12:56  keymap.c
.rwxr-xr-x  25B jack 01 Mar 2025 12:56  rules.mk