Fix typo in api_development_overview.md ("movings parts" to "moving parts")

[russell-myers1]

Issue Description

The documentation in api_development_overview.md contains a typo in the phrase "movings parts" under the Overview section (line 7). It should be corrected to "moving parts" for accuracy and readability.

This issue impacts both the source markdown file in the repository and the live documentation on the QMK site.

File Location:
• [https://docs.qmk.fm/#/api_development_overview](Live Page URL)
• [https://github.com/qmk/qmk_firmware/blob/master/docs/api_development_overview.md](Markdown Source File)