Add comment parsing

demo/demo.csv

@@ -1,5 +0,0 @@
-65279,1179403647,1463895090
-3.1415927,2.7182817,1.618034
--40,-273.15
-13,42
-65537

demo/demo.rpy

@@ -0,0 +1,9 @@
+show black amogus # this is a comment
+# this is a full line comment
+what the heck
+"this is a string with a # comment"
+"this is a string over
+multiple lines"
+this is cool # comment
+
+huh

demo/src/main.rs

@@ -1,5 +1,5 @@
 use renrs;
 
 fn main() {
-    renrs::parse("demo.csv");
+    renrs::parse("demo.rpy");
 }