chore(README.md): clarify fallback parsers [ci skip]

Author: jedwards1211

README.md

@@ -104,15 +104,15 @@ export class Parser {
 import { tsParser } from 'babel-parse-wild-code'
 ```
 
-The parser used for `.ts` files.
+The fallback parser used for `.ts` files.
 
 ## `tsxParser`
 
 ```ts
 import { tsxParser } from 'babel-parse-wild-code'
 ```
 
-The parser used for `.tsx` files.
+The fallback parser used for `.tsx` files.
 
 ## `jsParser`