pkgdown: add secret #762

Job	Run time
Get R version	1s
Check / (4.1)	4m 34s
Check / (4.2)	4m 46s
Links / Validate Links	7s
Check / (4.3)	2m 54s
Check / (devel)	4m 49s
Documentation	0s
Render README	0s
Validation	0s
Lint / Lint	4m 46s
Man Pages / Roxygen	4m 26s
Spelling / Spellcheck	4m 41s
Code Coverage / Test Coverage	5m 2s
Code Style / Code Style	4m 36s
Check Templates / Verify	4m 36s
Code Coverage / Generate badge for coverage	4s
	45m 22s

Provide feedback