Create 747-8i, includes image.

[MarylandFlyer]

More range, more efficiency, higher cost, fewer seats than the 747-400.

[patsonluk]

For new airplane PR, please refer to an example from https://github.com/patsonluk/airline/pull/164/files

Sorry I just found out i don't have any threads for the guide lines to add airplane, but just follow what the above PR did - that it requires:L

1. Adding ur model to the existing file, sorted by capacity so we can compare the parameters with other similar models easier
2. Require the actual image - crop to the specific dimension with transparent background and centered with landing gears visible - again please see the example PR for details