gitlab template in `README.md` is wrong

[ensc]

README.md contains

grcov/README.md

Lines 354 to 374 in 2cbc553

	# This is a multi-line command. You can also write it all as one line if desired, just remove
	# the '|' and all the newlines.
	- |
	grcov
	# This path must match the setting in LLVM_PROFILE_FILE. If you're not getting the coverage
	# you expect, look for '.profraw' files in other directories.
	target/coverage
	# If your target dir is modified, this will need to match...
	--binary-path target/debug
	# Where the source directory is expected
	-s .
	# Where to write the output; this should be a directory that exists.
	-o target/coverage
	# Exclude coverage of crates and Rust stdlib code. If you get unexpected coverage results from
	# this (empty, for example), try different combinations of '--ignore-not-existing',
	# '--ignore "$HOME/.cargo/**"' and see what kind of filtering gets you the coverage you're
	# looking for.
	--keep-only 'src/*'
	# Doing both isn't strictly necessary, if you won't use the HTML version you can modify this
	# line.
	--output-types html,cobertura

Using - | is wrong; this would require \ at the end of the lines.

Just write

    - grcov
    # This path must match the setting in LLVM_PROFILE_FILE. If you're not getting the coverage
    # you expect, look for '.profraw' files in other directories.
        target/coverage

[marco-c]

@ensc PRs welcome!