Update the docstr for `use_docker` in `execute_code`

[sonichi]

          Do we want to update the docstr? Like line 245?

Originally posted by @sonichi in #200 (review)

[Gourav2609]

Please assign this to me @sonichi

[sonichi]

Assigned. Thanks.

[Gourav2609]

Thanks @sonichi

[Gourav2609]

Hello @sonichi ... Please review the PR #233 ....do i need to changes something

[Gourav2609]

Thanks @sonichi @qingyun-wu for merging my PR ... can u please add hacktoberfest-accepted tag ....or else no problem

[sonichi]

Thanks. Added.