Correct some broken grammar / spelling / syntax / etc.

See https://duckduckgo.com/?q=english+grammar&ia=web ;
https://duckduckgo.com/?q=english+spelling&ia=web and for the lighter side:

* https://www.youtube.com/watch?v=8Gv0H-vPoDc

* https://shlomif.livejournal.com/53966.html

* http://i.imgur.com/HL1ZR.jpg .

FAQ.docbook5.xml.tt2

@@ -505,7 +505,7 @@ which is system-dependent.
 <para>
 The O’Reilly book
 <link xlink:href="http://www.lemis.com/grog/Documentation/PUS/">Porting
-UNIX Software</link> (available for purchase, or a free
+UNIX Software</link> (which is available for purchase, or as a free
 download under a Creative Commons licence, on the link), goes
 into further depth about these and many other UNIX portability
 issues.

FAQ.mdwn

@@ -271,10 +271,10 @@ is subject to many system-dependent factors, such as:
   64-bit, etc., which is system-dependent.
 
 The O’Reilly book [Porting UNIX
-Software](http://www.lemis.com/grog/Documentation/PUS/) (available for
-purchase, or a free download under a Creative Commons licence, on the
-link), goes into further depth about these and many other UNIX
-portability issues.
+Software](http://www.lemis.com/grog/Documentation/PUS/) (which is
+available for purchase, or as a free download under a Creative Commons
+licence, on the link), goes into further depth about these and many
+other UNIX portability issues.
 
 In any case, the best way to mitigate this problem portably and safely,
 is to write (and later read) every field (and sometimes every byte

FAQ_with_ToC__generated.md

@@ -362,10 +362,10 @@ is subject to many system-dependent factors, such as:
   64-bit, etc., which is system-dependent.
 
 The O’Reilly book [Porting UNIX
-Software](http://www.lemis.com/grog/Documentation/PUS/) (available for
-purchase, or a free download under a Creative Commons licence, on the
-link), goes into further depth about these and many other UNIX
-portability issues.
+Software](http://www.lemis.com/grog/Documentation/PUS/) (which is
+available for purchase, or as a free download under a Creative Commons
+licence, on the link), goes into further depth about these and many
+other UNIX portability issues.
 
 In any case, the best way to mitigate this problem portably and safely,
 is to write (and later read) every field (and sometimes every byte