fix: typo heuristic (#53)

Author: Rotzbua

README.md

@@ -44,7 +44,7 @@ svgcheck [options] SOURCE
 | `-V`          | `--version`      | display the version number and exit                                               |
 | `-d RNG`      | `--rng=RNG`      | specify an alternate RNG file                                                     |
 | `-o FILENAME` | `--out=FILENAME` | specify an output filename, default to stdout                                     |
-| `-g`          | `--grey-scale`   | use a grey scale hieristic to determine what is white                             |
+| `-g`          | `--grey-scale`   | use a grey scale heuristic to determine what is white                             |
 |               | `--grey-level`   | cut off level between black and white                                             |
 
 ## Dependencies

svgcheck/run.py

@@ -67,7 +67,7 @@ def main():
     svg_options.add_option('-a', '--always-emit', action='store_true', default=False,
                            help='Emit the SVG file even if does not need repairing.  Implies -r')
     svg_options.add_option('-g', '--grey-scale', action='store_true',
-                           help='Use grey scaling hieristic to determine what is white')
+                           help='Use grey scaling heuristic to determine what is white')
     svg_options.add_option('--grey-level', default=381,
                            help='Level to use for grey scaling, defaults to 381')
     optionparser.add_option_group(svg_options)