feat(funcnamefromrelpathdefault): export built in func name generator

Exporting this function is a new feature that will allow developers to better utilise this function
in build scripts.|The function may also be used to create a custom generator to customise
`exportFunctions()` behaviour.

Author: george43g

src/index.ts

@@ -1,2 +1,2 @@
-export { ExportFunctionsConfig, exportFunctions } from './export-functions';
+export { ExportFunctionsConfig, exportFunctions, funcNameFromRelPathDefault } from './export-functions';
 export { default } from './default';