Add Changesets configuration and update development documentation (#1964)

Introduce Changesets for versioning and changelog generation, and
enhance development documentation to guide contributors on using
Changesets effectively.

.changeset/changelog.js

@@ -0,0 +1,32 @@
+const changelogFunctions = {
+  getReleaseLine: async (changeset, type, options) => {
+    let prefix = '🎉';
+    if (type === 'major') {
+      prefix = '🎉';
+    } else if (type === 'minor') {
+      prefix = '🚀';
+    } else if (type === 'patch') {
+      prefix = '🐛';
+    }
+    if (changeset && changeset.summary) {
+      const summary = changeset.summary || '';
+      if (summary.indexOf('Docs') > -1) {
+        prefix = '📝';
+      }
+      if (
+        summary.indexOf('Chore') > -1 ||
+        summary.indexOf('grafana-plugin-sdk-go') > -1 ||
+        summary.indexOf('compiled') > -1
+      ) {
+        prefix = '⚙️';
+      }
+      return [prefix, summary].join(' ');
+    }
+    return [prefix, changeset?.summary].join(' ');
+  },
+  getDependencyReleaseLine: async (changesets, dependenciesUpdated, options) => {
+    return '\n';
+  },
+};
+
+module.exports = changelogFunctions;