Add: OpenTTD 15.0-beta3 announcement

[2TallTyler]

Description

Long social message:

Did you have a lazy summer? Over at OpenTTD HQ, we did not!

We've been busy building bridges over stations, rerouting ships traveling in opposite directions, improving the user interface, adding support for NewGRF Badges, and fixing bugs.

Come help us test our work!
[link to OpenTTD.org news post]

Short social message:

OpenTTD 15.0-beta3 now available on Steam / our website.
You can now build bridges over stations!
[link to OpenTTD.org news post]

Steam image in the spirit of our new title game. 😄

News-15.0-beta3.zip

To Do

• Finish a few PRs from the 15.0 milestone
• Update the post date before merging

[stormcone]

The image has an off-by-one error: it should be 15.0-beta3. :)

[2TallTyler]

Oops, fixed! 🙂