Merge pull request #1910 from input-output-hk/jordan/m-of-n

Fix M of N typo

shelley/design-spec/delegation_design_spec.tex

@@ -686,8 +686,8 @@ \subsection{Addresses and Credentials}
 multi signature, or \emph{multi-sig}. For this, Cardano-Shelley will feature a
 minimalistic scripting language capable of expressing the requirement of having
 a specified subset of a given set of keys provide a signature. Examples include
-\emph{M of N} schemes, where a transaction can be authorised if at least \(N\)
-distinct keys, from a set of \(M\) keys, sign the transaction.
+\emph{M of N} schemes, where a transaction can be authorised if at least \(M\)
+distinct keys, from a set of \(N\) keys, sign the transaction.
 %
 By introducing multi-sig script credentials, in Shelley, it will be possible to
 require single or multiple signatures both for the spending of funds and for the