Addressing feedback (and whitespace)

Addressing @fantasai's feedback and removing double-whitespace-after-period.

Author: cwilso

CONTRIBUTING.md

@@ -46,22 +46,22 @@ so if you believe an issue is urgent or discussion has stalled for awhile and
 the WG's attention is needed to move forward, ask one of the Editors to flag it.
 
 In general, you should not directly commit changes to a draft unless you are an
-Editor of that draft, or have their explicit permission.  If you are not an 
+Editor of that draft, or have their explicit permission. If you are not an 
 Editor of a draft, but wish to contribute changes, the best practice is to either 
 work directly with an Editor to review proposed text, or file your proposal as a 
 pull request (PR). Substantive changes need WG consensus, not merely Editor 
 agreement; typographic error and markup fixes are generally okay to commit, but 
-any substantive changes, or even substantial changes/additions to non-normative
-text, should have clear WG consensus.
+any substantive changes should have clear WG consensus. Substantial changes or
+additions to non-normative text should still have clear Editor approval.
 
 In any case, WG consensus is expected prior to merging changes, and consensus is 
 determined by the Chairs (not self-assessed) via synchronous decisions during 
 meetings, and occasionally via async CFCs. Some degree of discretion is afforded 
 to Editors to make changes prior to WG consensus, particularly early in a spec or 
-feature's lifecycle, although Editors should confirm those changes with the WG 
-prior to republishing on TR.  References to the discussion and the WG consensus 
-should be placed in the issue or commit.  Agreement from an Editor in an issue 
-is not a replacement for WG consensus.
+feature's lifecycle, although Editors must confirm those changes with the WG 
+prior to republishing on TR. References to the discussion and the WG consensus 
+should be placed in the issue or commit. Agreement from an Editor in an issue 
+is not a substitute for WG consensus.
 
 The Working Group, aside from managing issues on GitHub, mainly discusses
 specifications and requests on [the www-style public mailing list](https://lists.w3.org/Archives/Public/www-style/),