[3.x] Rewrite most of Resource's documentation #228

Job	Run time
📊 Static / Static Checks (clang-format, black format, file format, documentation checks)	2m 31s
🍏 iOS / Template (target=release, tools=no)	1m 19s
🐧 Linux / Editor w/ Mono (target=release_debug, tools=yes)	30m 4s
🌐 JavaScript / Template (target=release, tools=no)	2m 33s
🤖 Android / Template (target=release, tools=no)	2m 57s
🐧 Linux / Editor and sanitizers (target=debug, tools=yes, use_asan=yes, use_ubsan=yes, linker=gold)	32m 35s
🐧 Linux / Template w/ Mono (target=release, tools=no)	1m 26s
🍎 macOS / Editor (target=release_debug, tools=yes)	1m 49s
☁ Server / Linux Headless w/ Mono (target=release_debug, tools=yes)	18m 31s
🍎 macOS / Template (target=release, tools=no)	1m 18s
☁ Server / Linux Server w/ Mono (target=release, tools=no)	59s
🏁 Windows / Editor (target=release_debug, tools=yes)	19m 15s
🏁 Windows / Template (target=release, tools=no)	2m 59s
	1h 58m 16s

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