added definition of callback hell

[KatKowalik]

This PR fixes...

This PR adds a definition for "callback hell" to the dictionary.

What I did...

I added a definition for "callback hell" to the Dictionary.

How to test...

1. Navigate to https://cherryon.tech/dictionary/
2. Search the "callback hell" term.
3. Read the definition.

I learned...

I learned that the alternative name for Callback Hell is the Pyramid of Doom, and I think I like this term better 😆

[alliequintano]

Hey! @khairahscorner pointed out to me that our build is failing for reasons unrelated to your PR. I am fixing that now and will update when it's working again! Sorry about that.

[alliequintano]

I am going to close and re-open your PR to retrigger the Netlify checks. A little weird but should work :D

[alliequintano]

I am going to close and re-open your PR to retrigger the Netlify checks. A little weird but should work :D

Okay that didn't work, but I pushed an empty commit to retrigger the checks and now your Netlify preview is ready!!

[alliequintano]

Get job so far @KatKowalik! Can you please fill out the PR description with the template provided?

[KatKowalik]

@alliequintano Done! :)

[KatKowalik]

@alliequintano I changed the beginning to be a sentence, the rest I think looked fine, but let me know if you want me to change it.

[khairahscorner]

Merging this PR since all looks good! @shelleymcq your suggestion would be a great addition too!