fixup PseudoStash docs

(whitespace, spelling, grammar)

Author: coke

doc/Type/PseudoStash.pod6

@@ -8,7 +8,7 @@
 
 C<PseudoStash> is the stash type (hanging off C<.WHO>) that backs
 various pseudo-packages. So, when you do C<MY::> or C<CALLER::>, that
-gives back a C<PseudoStash>. In most cases, C<PackageName::> gives
+gives back a C<PseudoStash>. In most cases, C<Package::> gives
 back a C<Stash>. Neither of these are objects the user is expected to
 create by themselves, but in case you have one, you can just use it like a
 hash.
@@ -18,7 +18,7 @@ my $a = 42;
 my $b = q/$a/;
 dd MY::{$b}
 
-This shows how you can use a seudo-stash to look variables, by name,
-at runtime. 
+This shows how you can use a C<PseudoStash> to look up variables, by name,
+at runtime.
 
 =end pod

xt/words.pws

@@ -800,6 +800,7 @@ proto's
 protoregexes
 prototyped
 pseudopackage
+pseudostash
 ptrdiff
 punct
 pvalname