The snippet contains a |CHART_VERSION| directive that is not substituted
when generating the docs, because it's under a "code-block" directive
instead of a "parsed-literal".

Fix the directive, adjust backslashes accordingly, and remove the
redundant "--version" argument (already generated when expanding
|CHART_VERSION|).

Trim trailing white spaces in the file.

Fixes: b76f928 ("docs: add Helm configuration instructions for metrics")
Signed-off-by: Quentin Monnet <qmo@qmon.net>

For "parsed-literal" blocks, we need a double-backslash at the end of
the line to make a single "\" appear in the generated HTML docs. With a
single one in the source, Sphinx remove the line breaks and leaves
multiple spaces (from the indentation on the next line) instead.

Go through multiple locations (all that I could find) in the docs where
we have parsed-literal blocks with single backslashes to mark a command
split, and adjust with double backslashes instead.

For .../sbom.rst, also add the missing indentation marking the
continuation of the command line.

Trim trailing white spaces, if any, in all edited files.

Signed-off-by: Quentin Monnet <qmo@qmon.net>