README.md: typo fix (#970)

Signed-off-by: Steffen Pankratz <[email protected]>

Author: kratz00

README.md

@@ -75,7 +75,7 @@ Run the linter with:
 ./node_modules/.bin/tslint -c tslint.json
 ```
 
-TSLint will now complain that there are rules which require type checking. In order to fix this, use thw `-p` config option:
+TSLint will now complain that there are rules which require type checking. In order to fix this, use the `-p` config option:
 
 ```bash
 ./node_modules/.bin/tslint -p tsconfig.json -c tslint.json