Remove Rakudo filenames

Readers of this doc don't need to know where in Rakudo things are
defined.

Move all the Types to a separate line, following the new standard.

doc/Programs/03-environment-variables.rakudoc

@@ -37,21 +37,27 @@ to use a arguments with spaces in them.
 =head2 Module loading
 
 X<|Programs,RAKUDOLIB>X<|Programs,RAKULIB>X<|Programs,PERL6LIB>
-=item C<RAKUDOLIB>, C<RAKULIB> (I<Str>; B<src/core/Inc.pm>)
+=item C<RAKUDOLIB>, C<RAKULIB>
+
+Type: L<C<Str>|/type/Str>.
 
 C<RAKUDOLIB> and C<RAKULIB> append a comma-delimited list of paths to the
 search list for modules. C<RAKUDOLIB> is evaluated first. B<NOTE:> These env
 vars were added in the Rakudo compiler in version 2020.05. The deprecated older
 env var C<PERL6LIB> is still available.
 
 X<|Programs,RAKUDO_MODULE_DEBUG>
-=item C<RAKUDO_MODULE_DEBUG> (I<Bool>; B<src/Perl6/ModuleLoader.nqp>)
+=item C<RAKUDO_MODULE_DEBUG>
+
+Type: L<C<Bool>|/type/Bool>.
 
 If true, causes the module loader to print debugging information to standard
 error.
 
 X<|Programs,RAKUDO_PRECOMPILATION_PROGRESS>
-=item C<RAKUDO_PRECOMPILATION_PROGRESS> (I<Bool>; B<src/Perl6/ModuleLoader.nqp>)
+=item C<RAKUDO_PRECOMPILATION_PROGRESS>
+
+Type: L<C<Bool>|/type/Bool>.
 
 Available as of the 2012.12 release of the Rakudo compiler.
 
@@ -81,44 +87,54 @@ such as IDEs.
     # {"X::AdHoc":{"payload":"foo","message":"foo"}}
 
 X<|Programs,RAKUDO_NO_DEPRECATIONS>
-=item C<RAKUDO_NO_DEPRECATIONS> (I<Bool>; B<src/core.c/Deprecations.rakumod>)
+=item C<RAKUDO_NO_DEPRECATIONS>
+
+Type: L<C<Bool>|/type/Bool>.
 
 If true, suppresses deprecation warnings triggered by the C<is DEPRECATED>
 trait.
 
 X<|Programs,RAKUDO_DEPRECATIONS_FATAL>
-=item C<RAKUDO_DEPRECATIONS_FATAL> (I<Bool>; B<src/core.c/Deprecations.rakumod>)
+=item C<RAKUDO_DEPRECATIONS_FATAL>
+
+Type: L<C<Bool>|/type/Bool>.
 
 If true, deprecation warnings become thrown exceptions.
 
 X<|Programs,RAKUDO_VERBOSE_STACKFRAME>
-=item C<RAKUDO_VERBOSE_STACKFRAME> (I<UInt>; B<src/core.c/Backtrace.rakumod>)
+=item C<RAKUDO_VERBOSE_STACKFRAME>
+
+Type: L<C<Uint>|/type/Uint>.
 
 Displays source code in stack frames surrounded by the specified number of
 lines of context; for instance C<RAKUDO_VERBOSE_STACKFRAME = 1> will use one
 context line.
 
 X<|Programs,RAKUDO_BACKTRACE_SETTING>
-=item C<RAKUDO_BACKTRACE_SETTING> (I<Bool>; B<src/core.c/Backtrace.rakumod>)
+=item C<RAKUDO_BACKTRACE_SETTING>
+
+Type: L<C<Bool>|/type/Bool>.
 
 Controls whether C<.setting> files are included in backtraces.
 
 =head2 Affecting precompilation
 
 X<|Programs,RAKUDO_PREFIX>
-=item C<RAKUDO_PREFIX> (I<Str>; B<src/core.c/CompUnit/RepositoryRegistry.rakumod>)
+=item C<RAKUDO_PREFIX>
+
+Type: L<C<Str>|/type/Str>.
 
 When this is set, Rakudo will look for the standard repositories (perl, vendor,
 site) in the specified directory. This is intended as an escape hatch for
 build-time bootstrapping issues, where Rakudo may be built as an unprivileged
 user without write access to the runtime paths in NQP's config.
 
 X<|Programs,RAKUDO_PRECOMP_DIST>
-=item C<RAKUDO_PRECOMP_DIST> (B<src/core.c/CompUnit/PrecompilationRepository.rakumod>)
+=item C<RAKUDO_PRECOMP_DIST>
 X<|Programs,RAKUDO_PRECOMP_LOADING>
-=item C<RAKUDO_PRECOMP_LOADING> (B<src/core.c/CompUnit/PrecompilationRepository.rakumod>)
+=item C<RAKUDO_PRECOMP_LOADING>
 X<|Programs,RAKUDO_PRECOMP_WITH>
-=item C<RAKUDO_PRECOMP_WITH> (B<src/core.c/CompUnit/PrecompilationRepository.rakumod>)
+=item C<RAKUDO_PRECOMP_WITH>
 
 These are internal variables for passing serialized state to precompilation jobs
 in child processes. Please do not set them manually.
@@ -178,7 +194,9 @@ L«C<$*DEFAULT-READ-ELEMS>|/language/variables#$*DEFAULT-READ-ELEMS» dynamic
 variable.
 
 X<|Programs,RAKUDO_ERROR_COLOR>
-=item C<RAKUDO_ERROR_COLOR> (I<Bool>; B<src/core.c/Exception.rakumod>)
+=item C<RAKUDO_ERROR_COLOR>
+
+Type: L<C<Bool>|/type/Bool>.
 
 Controls whether to emit ANSI codes for error highlighting. Defaults to true
 if unset, except on Windows.
@@ -192,7 +210,9 @@ the C<REPL>.  This allows the C<REPL> to be better integrated in the Emacs
 environment (which sets this environment variable).
 
 X<|Programs,RAKUDO_MAX_THREADS>
-=item C<RAKUDO_MAX_THREADS> (I<UInt>; B<src/core.c/ThreadPoolScheduler.rakumod>)
+=item C<RAKUDO_MAX_THREADS>
+
+Type: L<C<Uint>|/type/Uint>.
 
 Indicates the maximum number of threads used by default when creating a
 L<C<ThreadPoolScheduler>|/type/ThreadPoolScheduler>. Defaults to 64 unless there appear to be more than
@@ -203,7 +223,9 @@ specify "B<unlimited>" or "B<Inf>" to indicate that the number of threads
 available by the operating system, will be the limiting factor.
 
 X<|Programs,TMPDIR>X<|Programs,TEMP>X<|Programs,TMP>
-=item C<TMPDIR>, C<TEMP>, C<TMP> (I<Str>; B<src/core.c/IO/Spec/>)
+=item C<TMPDIR>, C<TEMP>, C<TMP>
+
+Type: L<C<Str>|/type/Str>.
 
 The C<IO::Spec::Unix.tmpdir> method will return C<$TMPDIR> if it points to a
 directory with full access permissions for the current user, with a fallback
@@ -213,7 +235,9 @@ L<C<IO::Spec::Cygwin>|/type/IO::Spec::Cygwin> and L<C<IO::Spec::Win32>|/type/IO:
 which also include the C<%TEMP%> and C<%TMP%> environment variables.
 
 X<|Programs,PATH>
-=item C<PATH>, C<Path> (I<Str>; B<src/core.c/IO/Spec/>)
+=item C<PATH>, C<Path>
+
+Type: L<C<Str>|/type/Str>.
 
 The C<IO::Spec::Unix.path> method splits C<$PATH> as a
 shell would; i.e. as a colon-separated list. L<C<IO::Spec::Cygwin>|/type/IO::Spec::Cygwin> inherits this