Link explaining `respond_to_missing?` doesn't work

[JasonBarnabe]

ruby-style-guide/README.adoc

Line 5657 in 561f323

* Be sure to https://blog.marc-andre.ca/2010/11/15/methodmissing-politely/[also define `respond_to_missing?`]

https://blog.marc-andre.ca/2010/11/15/methodmissing-politely/ doesn't work.

[pirj]

@marcandre wdyt?
I recently noticed one of my sites on gh pages suddenly stopped working, too.