Introduced directories into the wiki and added content based on my talk with Bodo and my own thoughts

error-messages/Empty-file-error.md

+
+We could improve the error that you get when you try to compile an empty file by adding an example hello world program.
+
+## Error now:
+
+```
+Error:
+  No declaration of module, class, or main function given
+Compilation failed while Loading SAC program, 1 error(s).
+```
+
+## Error Proposal 
+
+```
+Error:
+  No declaration of module, class, or main function given
+Compilation failed while Loading SAC program, 1 error(s).
+
+Every program needs 1 main function. 
+Try a hello world program like this: 
+
+int main() {
+	show("Hello world!");
+}
+```
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