Document features automatically.

[futursolo]

Description

This pull request enables the doc_auto_cfg feature which documents the required feature flags automatically.

However, if an item is re-exported with pub use, it's not documented automatically unless the item itself has a #[doc(cfg(...))] or #[cfg(...)]. I have modified those to use #[cfg(...)] instead of #[doc(cfg(...))].

Checklist

• I have reviewed my own code
• I have added tests

[github-actions]

Visit the preview URL for this PR (updated for commit 3593765):

https://yew-rs-api--pr2780-doc-auto-cfg-a61n4l48.web.app

_{(expires Mon, 25 Jul 2022 04:48:17 GMT)}

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[github-actions]

Size Comparison

examples	master (KB)	pull request (KB)	diff (KB)	diff (%)
boids	173.452	173.449	-0.003	-0.002%
contexts	110.150	110.139	-0.012	-0.011%
counter	87.038	87.035	-0.003	-0.003%
counter_functional	87.704	87.702	-0.002	-0.002%
dyn_create_destroy_apps	90.148	90.147	-0.001	-0.001%
file_upload	103.506	103.503	-0.003	-0.003%
function_memory_game	168.673	168.671	-0.002	-0.001%
function_router	353.465	353.471	+0.006	+0.002%
function_todomvc	162.419	162.413	-0.006	-0.004%
futures	226.105	226.105	0	0.000%
game_of_life	107.727	107.725	-0.002	-0.002%
immutable	210.050	210.051	+0.001	+0.000%
inner_html	84.058	84.056	-0.002	-0.002%
js_callback	113.382	113.382	0	0.000%
keyed_list	195.879	195.874	-0.005	-0.002%
mount_point	86.681	86.681	0	0.000%
nested_list	116.269	116.265	-0.004	-0.003%
node_refs	93.981	93.981	0	0.000%
password_strength	1547.363	1547.365	+0.002	+0.000%
portals	97.874	97.871	-0.003	-0.003%
router	321.391	321.399	+0.009	+0.003%
simple_ssr	154.938	154.938	+0.001	+0.001%
ssr_router	399.949	399.668	-0.281	-0.070%
suspense	111.042	111.038	-0.004	-0.004%
timer	89.763	89.760	-0.003	-0.003%
todomvc	143.399	143.396	-0.003	-0.002%
two_apps	87.694	87.691	-0.003	-0.003%
web_worker_fib	154.721	154.710	-0.011	-0.007%
webgl	87.947	87.948	+0.001	+0.001%

✅ None of the examples has changed their size significantly.

[WorldSEnder]

Nice to see that this is finally possible with cargo doc