Add documentation for str.find

strings.zpy

@@ -142,7 +142,7 @@ These methods are available on both regular and Unicode strings.
 	a tab character, the current column is filled up with one or
 	more spaces, until the next column 'border' is reached. If there
 	are multiple tab characters in a row, the remaining tab
-	characters will fill up an entire column.
+	characters will fill up an entire column each.
 	
 	! Every character that is not a tab, newline or return, will be
 	  treated as being one position wide, even if they are not
@@ -151,3 +151,21 @@ These methods are available on both regular and Unicode strings.
 	tabsize::
 		**Optional.** The amount of spaces that a tab character
 		should be replaced with, at most. Defaults to 8.
+		
+^ .find(`sub`[, `start`[, `end`]])
+
+	Returns the first position in the string where the given
+	substring is found. If the substring is not found, the value
+	`-1` is returned.
+	
+	sub::
+		The substring to search for.
+		
+	start::
+		**Optional.** The starting point for the search. 
+		Interpreted as in slice notation. Defaults to the start
+		of the string.
+		
+	end::
+		**Optional.** The end point for the search. Interpreted
+		as in slice notation. Defaults to the end of the string.