Test

Add a dev theme to help with slide aspect ratio #5097

Job	Run time
find-languages	3s
cargo (ubuntu-latest)	25s
bare-metal (src/bare-metal/alloc-example, aarch64-unknown-none)	41s
cargo (macos-latest)	48s
format	28s
bare-metal (src/bare-metal/aps/examples, aarch64-unknown-none)	44s
bare-metal (src/bare-metal/microcontrollers/examples, thumbv7em-none-eabihf)	52s
bare-metal (src/exercises/bare-metal/compass, thumbv7em-none-eabihf)	42s
typos	7s
bare-metal (src/exercises/bare-metal/rtc, aarch64-unknown-none)	29s
build (bn)	6m 4s
build (da)	6m 7s
build (de)	6m 30s
build (el)	5m 36s
build (en)	6m 38s
build (es)	6m 22s
build (fa)	6m 40s
build (fr)	6m 2s
build (id)	6m 11s
build (it)	5m 53s
build (ja)	6m 30s
build (ko)	6m 49s
build (pl)	6m 7s
build (pt-BR)	6m 4s
build (ro)	6m 9s
build (ru)	5m 35s
build (tr)	5m 38s
build (uk)	5m 46s
build (zh-CN)	6m 52s
build (zh-TW)	6m 11s
	2h 9m 3s

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