Update docs to use Deno 1.10.x as 1.11

Deno 1.11 has just been released and it appears to be incompatible with the flat Deno package. Just updating the docs to use `1.10.x` until this is resolved.

#45

Author: GerryWilko

README.md

@@ -56,7 +56,7 @@ jobs:
       - name: Setup deno
         uses: denoland/setup-deno@main
         with:
-          deno-version: v1.x
+          deno-version: v1.10.x
       # Check out the repository so it can read the files inside of it and do other operations
       - name: Check out repo
         uses: actions/checkout@v2