Have completed the D8 port for this module & it can be found here - https...

Have completed the D8 port for this module & it can be found here - https://github.com/kunal-kursija/extlink_overlay

The following issues are covered in the github link mentioned above:
#2861089: Port info file to D8
#2861090: Port - README File
#2861091: Add Composer.json
#2861092: Add Static Files to D8 Port
#2861094: D8 Port of CSS File
#2861095: D8 Port of JS File
#2861096: D8 Port - Remove install file and add Configurations.
#2861098: D8 port: Add libraries.yml
#2861099: Port module file hooks to D8