Foundry adventures allow people to expand upon the default Foundry offerings are noted here.
To clone this repository, along with every adventure in it, use the following command:
git clone --recurse-submodules https://github.com/foundry-vtt-community/adventures.git
Instead, if you'd like to clone this repository and only fetch a specific adventure from it, use the following commands:
git clone https://github.com/foundry-vtt-community/adventures.git
cd adventures
git submodule init
git submodule update name-of-the-adventure
A quick note by u2mad: I've gotten permission to distribute this from the folks at Frog God games as long as the book/pdf for the adventure is still required and it isn't being sold.