fix(validateAndCoerceTypes): add a node for #help-fix doc

src/lib/validateAndCoerceTypes.ts

@@ -336,6 +336,12 @@ or open a new issue (and mention the symbol):  ${pkg.name} v${pkg.version}
 
 For information on how to turn off the above logging or skip these errors,
 see https://github.com/gadicc/node-yahoo-finance2/tree/devel/docs/validation.md.
+
+At the end of the doc, there's also a section on how to
+[Help Fix Validation Errors](https://github.com/gadicc/node-yahoo-finance2/blob/devel/docs/validation.md#help-fix)
+in case you'd like to contribute to the project.  Most of the time, these
+fixes are very quick and easy; it's just hard for our small core team to keep up,
+so help is always appreciated!
 `);
     } /* if (logErrors) */