spring, autumn and winter icons (plant, maple leaf and snowflake)
![image](https://github.com/atisawd/boxicons/assets/32953586/74d57fe2-a008-42f9-858e-81bd73b890a3)
Sun icon is already in, and looks nice, but would love to have icons to represent spring (plant), autumn (maple leaf) and winter (snowflake) in the style of the sun icon that already exists! adding image for inspiration, but they are not the same style as the sun icon