Remove trailing white-space from md files under content/tokio/

[AlfredWilmot]

Trailing white-space was programmatically removed from .md files using bash:

find ./content/tokio/ -name "*.md" | xargs -I {} sed -E -i 's/\s+$//' {}

Both doc-test and tutorial-code tests are passing following the changes introduced by this PR:

cd doc-test/
RUSTFLAGS="--cfg tokio_unstable" cargo +nightly test

Note

Although not related to this PR, it looks like there are no unit-tests in the tutorial code:

cd tutorial-code/
cargo test --all

At first I though I might need to configure the RUSTFLAG (similar to doc-test), however this check confirms there aren't any unit-tests in tutorial-code/ at present:

find tutorial-code/ -name "*.rs" | xargs -I {} grep "test" {} | wc -l
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