Remove indentation causing RST errors

[melissamahoney-mongodb]

We generate our docs in RST from Cobra. I removed the indentations causing an error in the generated RST. This also makes the long descriptions consistent with the other completion commands.

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This PR is being marked as stale due to a long period of inactivity

[marckhouzam]

I think this PR is giving problems:

1. it removes indentation while #1444 adds indentation. When both are joined in #1525 we are not consistent with the indentation between completion bash -h and the other shells (e.g., completion zsh -h)
2. the indentation allows nice code-block formatting in markdown, so I feel it is better to have it than not

@melissamahoney-mongodb can you specify how you get an error when generating RST doc? I haven't been able to reproduce it.

@umarcor what do you think? I personally would pull this out of the release candidate until we can clarify the situation.

[umarcor]

@marckhouzam I removed this from #1496 and I pulled it out of #1525.

It seems that supporting multiple output formats might require explicitly handling multiple text sources...