Fix typos.

ProofMode.md

@@ -124,8 +124,8 @@ The later modality
 
 - `iNext n` : introduce `n` laters by stripping that number of laters from all
   hypotheses. If the argument `n` is not given, it strips one later if the
-  leftmost conjuct is of the shape `▷ P`, or `n` laters if the leftmost conjuct
-  is of the shape `▷^n P`.
+  leftmost conjunct is of the shape `▷ P`, or `n` laters if the leftmost
+  conjunct is of the shape `▷^n P`.
 - `iLöb as "IH" forall (x1 ... xn) "selpat"` : perform Löb induction by
   generating a hypothesis `IH : ▷ goal`. The tactic generalizes over the Coq
   level variables `x1 ... xn`, the hypotheses given by the selection pattern