Fixes in 1986, manifest update

The html files in 1986 (including 1986/marshall/compilers.html) look and
feel good. Format change (slight) in 1986/marshall/index.html.

The manifest update includes a fix for 1986/hague and this same change
in entry_text applies to files in a few other years as well.

1986/marshall/compilers.md

@@ -91,7 +91,7 @@ And that is the tale of a little <del>engine</del> train that
 could...eventually! Or perhaps it's the compilers, optimisers and OSes that
 eventually could?
 
-Whichever you wish it to be, it now works with both `clang` and `cc` Choo choo!
+Whichever you wish it to be, it now works with both `clang` and `cc`. Choo choo!
 
 
 <hr style="width:10%;text-align:left;margin-left:0">