Added some details to README ..

README.md

@@ -1,12 +1,19 @@
 # fntdump
-A tool to convert binary 8x16 .FNT files to/from 'ASCII art' text file dumps to allow editing glyphs in a text editor
+A tool to convert binary 8x16 .FNT files to/from 'ASCII art' text file dumps to allow editing glyphs in a text editor.
+
+This should be able to build on both linux (tested) and MS-DOS (Turbo C 3).
+Currently only 8x16 monospaced bitmap fonts are supported.
+(I believe 8xN fonts are also supported, where N <= 16, since they seem to just be padded out to 8x16)
 
 Example usage:
 
     fntdump SOMEFONT.FNT SOMEFONT.TXT   -- convert font to an 'ascii art' .txt file
-    vi SOMEFONT.TXT                     -- edit the 'ascii art' to make changes to the font's bitmap
-    fntdump SOMEFONT.TXT NEWFONT.FNT    -- convert the 'ascii art' back into a new .fnt file
+    vi SOMEFONT.TXT                     -- edit the 'ascii art' .txt file to change font's bitmap
+    fntdump SOMEFONT.TXT NEWFONT.FNT    -- convert the 'ascii art' .txt back into a new .fnt file
 
+Basically you just change around the 'X's and '.'s to the way you want them, without
+changing the length of the line, or the number of lines per character (must be 16).
+
 The format of the 'ascii art' file is meant to be easy to edit in a text editor,
 so you can change the glyphs around by simply changing the ascii content. Example: