docs: Mention cooldown in dependabot config (#247)

Author: pavelzw

.github/dependabot.yml

@@ -8,6 +8,8 @@ updates:
       gh-actions:
         patterns:
           - '*'
+    cooldown:
+      default-days: 7
   - package-ecosystem: npm
     directory: /
     schedule:
@@ -16,3 +18,5 @@ updates:
       nodejs:
         patterns:
           - '*'
+    cooldown:
+      default-days: 7

README.md

@@ -51,6 +51,8 @@ GitHub Action to set up the [pixi](https://github.com/prefix-dev/pixi) package m
 >       dependencies:
 >         patterns:
 >           - '*'
+>     cooldown:
+>       default-days: 7
 > ```
 
 ## Features