update NEC PC-6001 files to yaff format

nec-pc/README.md

@@ -1,7 +1,7 @@
 NEC PC-9800 series
 ------------------
 
-The `nec-pc98-*` files are taken from the character ROM of a NEC PC-9821 Ce2 model S2D.
+The `nec-pc98*` files are taken from the character ROM of a NEC PC-9821 Ce2 model S2D.
 There are two single-byte character sets and one Kanji set. The single-byte sets follow
 an [extension of JIS x 0201](https://en.wikipedia.org/wiki/JIS_X_0201#/media/File:NEC-C-6220-paths.svg). The double-byte set is likely a form of Shift-JIS.
 
@@ -12,7 +12,13 @@ and the Kanji encoding still need to be mapped.
 NEC PC-8000 series
 ------------------
 
-The `nec-pc8001-*` files are taken from the character ROMs of a NEC PC-8001 and NEC PC-8001 Mk2SR. The latter included a Latin/Katakana set (identical to the PC-8001) and 
+The `nec-pc8001*` files are taken from the character ROMs of a NEC PC-8001 and NEC PC-8001 Mk2SR. The latter included a Latin/Katakana set (identical to the PC-8001) and 
 an additional Latin/Hiragana set. There is another ROM that includes 8x16 Latin/Kana and 16x16 Kanji - this has not yet been included.
 
 
+NEC PC-6000 series
+------------------
+
+The `nec-pc6001*` character sets are taken from character ROMs 
+for the PC-6001 and PC-6001A (TREK).
+