Undo apparent accidental @-color replaces in upstream TBA files. (#62)

I am guessing some script or tool used upstream is doing an unsafe
search-and-replace for '@' with TAB, and accidentally changing these.
They seem to have been creeping into the repo for years.

I produced this fix commit automatically with:
  sed -i 's|\t\([bcdgmnoruwyBCDGMRWY]\)|@\1|g' tba/*/*.*
...and then a few files' changes had to be undone.

I looked through all of the rest, and they look like correct fixes.

I also ran all the other letters, and they only make incorrect "fixes".

lib/world/wld/118.wld

@@ -634,7 +634,7 @@ subtle light at the bottom of the stairs.
 0 0 11810
 E
 sign~
-   	BMUM AND DAD'S ROOM	n
+   @BMUM AND DAD'S ROOM@n
 ~
 E
 nightlights~
@@ -2391,10 +2391,10 @@ Once you have counted them all, type look next
 118 24 0 0 0 0
 E
 two 2~
-	y	RF	yINISHED 	RF	yILES ARE THE RE-
-SULT O	RF	y YEARS O	RF	y SCIENTI	RF	y-
+@y@RF@yINISHED @RF@yILES ARE THE RE-
+SULT O@RF@y YEARS O@RF@y SCIENTI@RF@y-
 IC STUDY COMBINED WITH THE
-EXPERIENCE O	RF	y YEARS...	n
+EXPERIENCE O@RF@y YEARS...@n
 ~
 E
 next~