doc/go1.14: add missing period at sentence end

Change-Id: I82050f16906e7d34555a592e96b7855515a1726a
Reviewed-on: https://go-review.googlesource.com/c/go/+/219641
Reviewed-by: Tobias Klauser <[email protected]>

Author: ALTree

doc/go1.14.html

@@ -378,7 +378,7 @@ <h2 id="compiler">Compiler</h2>
 <p><!-- CL 204338 -->
   The compiler can now emit machine-readable logs of key optimizations
   using the <code>-json</code> flag, including inlining, escape
-  analysis, bounds-check elimination, and nil-check elimination
+  analysis, bounds-check elimination, and nil-check elimination.
 </p>
 
 <p><!-- CL 196959 -->