Add Olimex_MOD-WIFI-ESP8266-DEV module

This module is produced as OSHW by Olimex. All datasheets are available at https://www.olimex.com/Products/IoT/ESP8266/MOD-WIFI-ESP8266-DEV/open-source-hardware

Footprint MR: kicad-footprints!2773 (merged)

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General Guidelines:

All contributions to the kicad library must follow the KiCad library convention

Thanks for creating a pull request to contribute to the KiCad libraries! To speed up integration of your PR, please check the following items:

• Provide a URL to a datasheet for the symbol(s) you are contributing
• An example screenshot image is very helpful
• Ensure that the associated footprints match the official footprint library
  • A new fitting footprint must be submitted if the library does not yet contain one.
• If there are matching footprint PRs, provide link(s) as appropriate
• Check the output of the automated check scripts - fix any errors as required
• Give a reason behind any intentional library convention rule violation.