Add grouping feature to syntax guide

src/content/docs/guides/syntax.md

@@ -64,4 +64,14 @@ if ("block ~ ~-1 ~ minecraft:stone") {
 } else {
     /say Not on stone
 }
+```
+
+## Groupings
+Groupings are used to group multiple commands together into one `mcfunction` file without declaring a new function.
+This can be used for commands that need to be executed atomically.
+```shulkerscript
+group {
+    /say Hello
+    /say World
+}
 ```