doc: fix punctuation in v8.md

Two minor punctuation fixes for v8.md.

PR-URL: #36192
Reviewed-By: Antoine du Hamel <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Richard Lau <[email protected]>

Author: Trott

Diff for: doc/api/v8.md

@@ -231,12 +231,12 @@ added: v15.1.0
 
 The `v8.takeCoverage()` method allows the user to write the coverage started by
 [`NODE_V8_COVERAGE`][] to disk on demand. This method can be invoked multiple
-times during the lifetime of the process, each time the execution counter will
+times during the lifetime of the process. Each time the execution counter will
 be reset and a new coverage report will be written to the directory specified
 by [`NODE_V8_COVERAGE`][].
 
 When the process is about to exit, one last coverage will still be written to
-disk, unless [`v8.stopCoverage()`][] is invoked before the process exits.
+disk unless [`v8.stopCoverage()`][] is invoked before the process exits.
 
 ## `v8.stopCoverage()`