add clear call to send PRs (#1449)

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Co-authored-by: Brian Sperlongano <zelonewolf@gmail.com>

Author: matkoniecz

CONTRIBUTING.md

@@ -36,6 +36,8 @@ Read the [GUIDELINES](./GUIDELINES.md) to help you understand what fields and ta
 
 ## Making Changes
 
+You are highly welcome to help this project by submitting pull requests!
+
 ### Overview and General Structure
 
 Detailed documentation for the data format used in this repository is located with the [schema-builder](https://github.com/ideditor/schema-builder) package, which is the technical basis of this project.