doc: Add cindex entries for existing About

* doc/about.texi: Add miscellaneous entries.

doc/about.texi

@@ -54,6 +54,9 @@ The input grammar is XML,
 
 @node Getting Started
 @section Getting Started
+@cindex Saxon
+@cindex HOXSL
+@cindex bootstrap
 To get started,
   make sure Saxon version@tie{}9 or later is available and its path
   set as @var{SAXON_CP};
@@ -74,10 +77,11 @@ $ ./boostrap
 
 @node Manual Compilation
 @section Manual Compilation
-@emph{Note: TAME is usually controlled through a Makefile;
+@tip{Note: TAME is usually controlled through a Makefile;
         @pxref{Compiling With Make} to avoid manual compilation
         steps.}
 
+@cindex tamed
 @tame{} is controlled through the program in @command{bin/tame}.
 When run,
   it first spawns a daemon @command{bin/tamed} if it is not already
@@ -109,6 +113,7 @@ For additional options and environment variables that influence
 
 @node Compiling With Make
 @section Compiling With Make
+@cindex Make
 TAME can generate a @url{https://gnu.org/software/make,GNU Makefile}
   for you using @url{https://gnu.org/software/automake,Automake} and
   @url{https://gnu.org/softeware/autoconf,Autoconf}.
@@ -117,6 +122,7 @@ This greatly simplifies building projects by automatically building
     and only when they have changed.@footnote{@c
       When their modification timestamps change, specifically.}
 
+@cindex Makefile
 The Makefile is generated by a @file{configure} script,
   which itself generated by Autoconf using @file{configure.ac} in the
   project root:
@@ -132,6 +138,7 @@ m4_include([rater/build-aux/m4/calcdsl.m4])
 @caption{Example @file{configure.ac} in project root.}
 @end float
 
+@cindex submodule
 By convention,
   TAME is usually available as a submodule under @file{rater/}.
 This confusing naming convention may change in the future.