Typo fixes in inc/ and next/

A typo that was missed because I did not look at that part of the file
was 'quidelines' instead of 'guidelines'. This has been fixed in inc/
and next/.

inc/rules.open.hdr

@@ -10,7 +10,7 @@ will remain **OFFICIAL** for this IOCCC.
 
 See our [FAQ about providing feedback](../faq.html#feedback) as well
 as our [FAQ about asking questions](../faq.html#question) about
-these quidelines.
+these guidelines.
 
 **SUGGESTION**: Watch both the [IOCCC news](../news.html) and the
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