Structures Addition

Datapack adding some small structures. Other structures will arrive soon. This is my first time posting something about Minecraft. Other structures will arrive soon, I hope you like it! Do not hesitate to give me your feedback.

Dolmen this structure appears in:

• plains
• swamp
• taiga
• old_growth_pine_taiga
• old_growth_spruce_taiga
• jungle, sparse_jungle
• savanna
• savanna_plateau