added full DSL Grammer to ColumnSelectors.md

Author: Jolanrensen

docs/StardustDocs/topics/ColumnSelectors.md

@@ -21,6 +21,24 @@ df.move { name.firstName and name.lastName }.after { city }
 <dataFrame src="org.jetbrains.kotlinx.dataframe.samples.api.Access.columnSelectorsUsages.html"/>
 <!---END-->
 
+#### Full DSL Grammar:
+
+**Definitions**
+
+<dataFrame src="org.jetbrains.kotlinx.dataframe.api.ColumnsSelectionDsl.DslGrammar.DefinitionsPartOfGrammar.html"/>
+
+<tabs>
+    <tab title="Directly in the DSL">
+        <dataFrame src="org.jetbrains.kotlinx.dataframe.api.ColumnsSelectionDsl.DslGrammar.PlainDslPartOfGrammar.html"/>
+</tab>
+    <tab title="On a Column Set">
+        <dataFrame src="org.jetbrains.kotlinx.dataframe.api.ColumnsSelectionDsl.DslGrammar.ColumnSetPartOfGrammar.html"/>
+</tab>
+    <tab title="On a Column Group">
+        <dataFrame src="org.jetbrains.kotlinx.dataframe.api.ColumnsSelectionDsl.DslGrammar.ColumnGroupPartOfGrammar.html"/>
+</tab>
+</tabs>
+
 **Select columns by name:**
 
 <!---FUN columnSelectors-->