linked-list: use tildes for admonition, not backticks

[ee7]

Commit d48e19a added an admonition that used backticks, but every other admonition uses tildes.

From the Exercism Markdown specification:

We support special types of blocks that can be added to documents to pull out commentary that doesn't fit with the main body of the text.

[...]

All blocks are written using 4 tildes, in the form of:

~~~~exercism/note
Content goes here

You can include code:
```ruby
str = "Hello, World"
```
~~~~

(Note: You may also use backticks or other levels of tildes in exceptional circumstances)

---

With this PR, every admonition uses tildes:

$ git rev-parse --short HEAD
84d547a2
$ git grep --break --heading 'exercism/' -- 'exercises/*.md'
exercises/binary:search/instructions.md
8:~~~~exercism/caution

exercises/counter/description.md
5:Please see the discussion in [https://github.com/exercism/problem-specifications/issues/80](https://github.com/exercism/problem-specifications/issues/80)

exercises/etl/instructions.md
25:~~~~exercism/note

exercises/gigasecond/introduction.md
16:~~~~exercism/note

exercises/killer:sudoku-helper/description.md
59:[one-solution-img]: https://media.githubusercontent.com/media/exercism/v3-files/main/julia/killer-sudoku-helper/example1.png
60:[four-solutions-img]: https://media.githubusercontent.com/media/exercism/v3-files/main/julia/killer-sudoku-helper/example2.png
61:[not-possible-img]: https://media.githubusercontent.com/media/exercism/v3-files/main/julia/killer-sudoku-helper/example3.png

exercises/linked:list/instructions.md
16:~~~~exercism/note

exercises/pangram/introduction.md
10:~~~~exercism/note

exercises/rational:numbers/description.md
5:~~~~exercism/note

exercises/rna:transcription/instructions.md
18:~~~~exercism/note

exercises/rna:transcription/introduction.md
7:~~~~exercism/note

exercises/secret:handshake/instructions.md
44:~~~~exercism/note

exercises/sieve/instructions.md
21:~~~~exercism/note

[kytrinyx]

Ugh, I thought I had fixed all these, and somehow missed this one. Thanks for fixing it.

[SleeplessByte]

If we don't add the prettier ignore thing, every place this is merged with formatting on or copied, it will break 💔

[ee7]

If we don't add the prettier ignore thing, every place this is merged with formatting on or copied, it will break 💔

I didn't understand this. Is there something that blocks merging? Please expand.

[BethanyG]

If we don't add the prettier ignore thing, every place this is merged with formatting on or copied, it will break 💔

I didn't understand this. Is there something that blocks merging? Please expand.

If you use prettier to auto-format things (and many tracks have this in place via a special command/comment), it will re-fomat the tildas (~~~) and turn them into backticks (```). To stop this behavior, you need to tell prettier to ignore the block (Markdown specific comment here).

We probably should adjust our documentation as well to point that out to folx who also use prettier locally. I know there have been multiple instances on the Python track where someone has used prettier and I've had to make them go back and re-do the ~~~ blocks (and they've argued with me about it).

edited to add: Conversely, we can change the way we do this and use backticks for admonitions. But I think we chose tildas for parsing reasons.

[ee7]

My understanding is that we can merge this. This PR just brings us back to the status quo: all 9 other admonitions in this repo use tildes.

If you use prettier to auto-format things (and many tracks have this in place via a special command/comment)

Can the track make prettier ignore files that are synced from prob-specs?