Proof Set and Chain Test Vectors: punctuation fix.

Co-authored-by: Ted Thibodeau Jr <[email protected]>

index.html

@@ -2049,7 +2049,7 @@ <h4>Proof Set</h4>
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           <p>
 Per the algorithm of <a data-cite="vc-data-integrity#add-proof-set/chain">
-Section 4.4: Add Proof Set/Chain</a> in [[VC-DATA-INTEGRITY]]
+Section 4.4: Add Proof Set/Chain</a> in [[VC-DATA-INTEGRITY]],
 we create an array variable <var>allProofs</var> and add the proof from the
 starting document to it. Since there is no `previousProof` attribute no
 modification of `unsignedDocument` is needed prior to computing the signed proof