Set targets for docs.rs in the hope to get the docs up

Signed-off-by: Daniel Egger <daniel@eggers-club.de>

Author: therealprof

Cargo.toml

@@ -24,7 +24,7 @@ version = "0.8.0"
 [package.metadata.docs.rs]
 features = ["stm32f429", "rt", "usb_fs"]
 rustdoc-args = ["--cfg", "docsrs"]
-default-target = "x86_64-unknown-linux-gnu"
+targets = ["thumbv7em-none-eabihf"]
 
 [dependencies]
 cortex-m = ">=0.5.8,<0.7"