Issue from rock5/rock5a/download

[RadxaYuntian]

没有datasheet的下载

[tangzz-radxa]

The ROCK 5A product brief (datasheet) PDF exists at https://dl.radxa.com/rock5/5a/docs/radxa_rock5a_product_brief.pdf but was missing from the download page. Fixed in PR #2001 — the link is now added to the Hardware Design section in both English and Chinese versions.