Create a documentation object class.

src/main/kotlin/org/nwapw/abacus/function/Documentation.kt

@@ -0,0 +1,15 @@
+package org.nwapw.abacus.function
+
+/**
+ * A data class used for storing information about a function.
+ *
+ * The Documentation class holds the information necessary to display the information
+ * about a function to the user.
+ *
+ * @param codeName the name of the function as it occurs in code.
+ * @param name the name of the function in English.
+ * @param description the short description of this function.
+ * @param longDescription the full description of this function.
+ */
+data class Documentation(val codeName: String, val name: String,
+                         val description: String, val longDescription: String)