announce: be more consistent in the use of markdown

docs/announce/2015.02.md

@@ -34,18 +34,18 @@ Some of the new compiler features added to this release include:
   This behaviour now matches the behaviour on the Parrot and JVM backend,
   therefore one could consider this a bug fix, rather than an incompatible
   change.
-+ Overriding invoke/postcircumfix:<( )> for type coercions (ex. MyType(...))
++ Overriding `invoke`/`postcircumfix:<( )>` for type coercions (ex.  `MyType(...)`)
   now passes the function arguments as-is, rather than just passing a Capture
   containing them. To get the old behavior, simply declare a Capture
   parameter (|c).
-+ "6;" at unit start is no longer a way to say "no strict;".  It was deemed
++ `6;` at unit start is no longer a way to say `no strict;`.  It was deemed
   to be a bad meme and huffmannized inappropriately.
 + Coercion syntax now works in signatures: sub foo(Str(Any) $a) { ... }
   will take Any value as its first positional parameter, and coerce it to
   Str before making it available in $a.  Note that Str(Any) can be shortened
   to Str().
-+ "sub MAIN;" (as in, rest of file is the MAIN unit) has been implemented.
-+ Metaop "=" now respects the precedence of the op it is meta-ing.
++ `sub MAIN;` (as in, rest of file is the MAIN unit) has been implemented.
++ Metaop `=` now respects the precedence of the op it is meta-ing.
 + Many optimizations, improved error messages and bugs fixed (over
   200 commits to Rakudo since the 2015.01 release).