README: consider listing the https install form first (ssh form fails on keyless machines)

Small docs suggestion: the install section lists npx skills add [email protected]:kepano/obsidian-skills.git first. On any machine without GitHub SSH keys configured (fresh boxes, CI, sandboxes) that form fails with an auth error, while the https form works everywhere:

npx skills add https://github.com/kepano/obsidian-skills

Leading with https (ssh as the alternative) would save first-time users a confusing failure. For context, we installed and ran the full five-pack while testing it for a write-up — 2.0s install, all five skills landed clean: https://skillstested.com/skills/obsidian/

One thing we appreciated and highlighted: four of the five skills are pure format knowledge and work without Obsidian installed at all — that's underadvertised.