docs: fix markdown for import code snippets

[eliobischof]

Uses codefile "bash" in templates for import commands, so that the templates render ```bash codeblocks instead of ```terraform codeblocks

Definition of Ready

• [ ] Short description of the feature/issue is added in the pr description
• [ ] PR is linked to the corresponding user story
• [ ] Acceptance criteria are met
• [ ] All open todos and follow ups are defined in a new ticket and justified
• [ ] Deviations from the acceptance criteria and design are agreed with the PO and documented.
• [ ] No debug or dead code
• [ ] My code has no repetitions
• [ ] All non-functional requirements are met
• [ ] The generic lifecycle acceptance test passes for affected resources.
• [ ] Examples are up-to-date and meaningful. The provider version is incremented.
• [ ] Docs are generated.
• [ ] Code is generated where possible.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 63.08%. Comparing base (9e1b675) to head (293d6e7). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #165 +/- ## ======================================= Coverage 63.08% 63.08% ======================================= Files 159 159 Lines 12891 12891 ======================================= Hits 8132 8132 Misses 3475 3475 Partials 1284 1284 ``` | [Flag](https://app.codecov.io/gh/zitadel/terraform-provider-zitadel/pull/165/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=zitadel) | Coverage Δ | | |---|---|---| | [acceptance-tests](https://app.codecov.io/gh/zitadel/terraform-provider-zitadel/pull/165/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=zitadel) | `63.08% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=zitadel#carryforward-flags-in-the-pull-request-comment) to find out more.

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