Add typos ignore file

[benegee]

See https://github.com/crate-ci/typos/issues/745#issuecomment-1884591285

Fixes #182

[sloede]

Fixes #182

Unfortunately not 😓

[codecov[bot]]

Codecov Report

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

Project coverage is 80.27%. Comparing base (ddd5dd8) to head (24bc27b). Report is 2 commits behind head on main.

:exclamation: Current head 24bc27b differs from pull request most recent head 27cd08f. Consider uploading reports for the commit 27cd08f to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #185 +/- ## ======================================= Coverage 80.27% 80.27% ======================================= Files 19 19 Lines 715 715 Branches 50 50 ======================================= Hits 574 574 Misses 137 137 Partials 4 4 ``` | [Flag](https://app.codecov.io/gh/trixi-framework/libtrixi/pull/185/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trixi-framework) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/trixi-framework/libtrixi/pull/185/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trixi-framework) | `80.27% <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=trixi-framework#carryforward-flags-in-the-pull-request-comment) to find out more.

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[sloede]

Why not just add a .typos.yml file to the main directory, to be consistent with Trixi.jl et al.?

[benegee]

I had not realized Trixi.jl was using it.