Added easyjson generation task in Taskfile

Author: cmaglie

Taskfile.yml

@@ -119,6 +119,13 @@ tasks:
     cmds:
       - go vet {{default .DEFAULT_GO_PACKAGES .GO_PACKAGES}}
 
+  go:easyjson-generate:
+    desc: Run easyjson code generation
+    cmds:
+      - go install github.com/mailru/easyjson/...@v0.7.7
+      - easyjson arduino/cores/packageindex/index.go
+      - easyjson arduino/libraries/librariesindex/json.go
+
   # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-markdown-task/Taskfile.yml
   markdown:check-links:
     desc: Check for broken links

docs/CONTRIBUTING.md

@@ -349,6 +349,13 @@ func main() {
 }
 ```
 
+### About `easyjson` golang library
+
+We use the hi-performance `easyjson` library to parse the large JSON index files for libraries and platforms. To obtain
+the best performance we must do some code generation, this is done via `task go:easyjson-generate`. If you ever touch
+source code using the `easyjson` library, make sure to re-run the `go:easyjson-generate` task to see if there are
+changes in the generated code.
+
 ### Additional settings
 
 If you need to push a commit that's only shipping documentation changes or example files, thus a complete no-op for the