Rollup merge of #44541 - GuillaumeGomez:openoptions-docs, r=QuietMisdreavus
Rollup merge of #44541 - GuillaumeGomez:openoptions-docs, r=QuietMisdreavus

Openoptions docs

r? @QuietMisdreavus

GBGamer/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,GBGamer/rust,graydon/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,graydon/rust,graydon/rust