Revises section on profiler

Which was masterfully done by @MasterDuke17. Closes #1921.

Also removes accidental MD, refs #2022.

doc/Language/performance.pod6

@@ -37,10 +37,10 @@ When using the L<MoarVM|http://moarvm.org> backend, the
 L<Rakudo|http://rakudo.org> compiler's C<--profile> command line option writes
 the profile data to an HTML file.
 
-It will open to the "Overview" section, which gives some overall data about how
+This file will open to the "Overview" section, which gives some overall data about how
 the program ran, e.g., total run time, time spent doing garbage collection. One
 important piece of information you'll get here is percentage of the total call
-frames (i.e., blocks) that were interpreted (slowest, in red), speshed (faster,
+frames (i.e., blocks) that were interpreted (slowest, in red), L<speshed|/language/glossary#index-entry-Spesh> (faster,
 in orange), and JITted (fastest, in green).
 
 The next section, "Routines", is probably where you'll spend the most time. It has
@@ -49,7 +49,7 @@ times it ran, the inclusive time (time spent in that routine + time spent in all
 routines called from it), exclusive time (just the time spent in that routine), and
 whether it was interpreted, speshed, or JITted (same color code as the "Overview"
 page). Sorting by exclusive time is a good way to know where to start optimizing.
-Routines with a filename that starts like `SETTING::src/core/` or `gen/moar/` are
+Routines with a filename that starts like C<SETTING::src/core/> or C<gen/moar/> are
 from the compiler, a good way to just see the stuff from your own code is to put
 the filename of the script you profiled in the "Name" search box.
 
@@ -107,7 +107,7 @@ of SQL statements, suitable for opening in SQLite.
     =end code
 
 To learn how to interpret the profile info, use the C<prof-m: your code goes
-here> evalbot (explained above) and ask questions on the channel.
+here> evalbot (explained above) and ask questions on the IRC channel.
 
 =head2 Profile compiling