Add .agents/skills skill storage paths in documentation

Added the `.agents/skills` project and personal paths as they are a convention stated in https://agentskills.io/client-implementation/adding-skills-support#where-to-scan for cross-client skill sharing.

Author: lewislbr

data/reusables/copilot/creating-adding-skills.md

@@ -6,9 +6,9 @@ To add a skill, you save the `SKILL.md` file, and any subsidiary resources, to a
 
 1. Create a `skills` directory to store your skill and any others you may want to create in the future.
 
-    For **project skills**, specific to a single repository, store your skill under `.github/skills` or `.claude/skills`.
+    For **project skills**, specific to a single repository, store your skill under `.agents/skills`, `.github/skills` or `.claude/skills`.
 
-    For **personal skills**, shared across projects, store your skill under `~/.copilot/skills` or `~/.claude/skills`.
+    For **personal skills**, shared across projects, store your skill under `~/.agents/skills`, `~/.copilot/skills` or `~/.claude/skills`.
 
 1. Create a subdirectory for your new skill. Each skill should have its own directory (for example, `.github/skills/webapp-testing`).