Minor wording amendment

Author: AnthonyLatsis

proposals/NNNN-adoption-tooling-for-swift-features.md

@@ -92,7 +92,7 @@ and testing code where a change in behavior is preferable.
 
 ## Proposed solution
 
-Introduce the notion of a ***migrate*** mode for individual experimental and
+Introduce the notion of a migration mode for individual experimental and
 upcoming features.
 The core idea behind migration mode is a declaration of intent that can be
 leveraged to build better supportive adoption experiences for developers.
@@ -150,8 +150,8 @@ be emitted.
 This warning will belong to the diagnostic group `StrictLanguageFeatures`.
 In a series of either of these options applied to a given feature, only the
 last option will be honored.
-If an upcoming feature is both implied by the effective language mode and
-enabled in migration, the latter will be disregarded.
+If a feature is both implied by the effective language mode and enabled in
+migration mode, the latter option will be disregarded.
 
 ### Diagnostics