Improve the library

[szepeviktor]

@mindplay-dk I've decided to put all things in one PR.

1. Stop distributing development files: git archive HEAD|tar --list
2. Fix typos
3. 1 Composer script/1 CI step
4. Fix gitignores: git ls-files --cached --ignored --exclude-standard
5. Move the logo to .github/

the theory

[mindplay-dk]

@szepeviktor do you know if, instead of this:

.github/ export-ignore
.gitattributes export-ignore
.gitignore export-ignore
.scrutinizer.yml export-ignore

can we just do:

.* export-ignore

(same as in the .gitignore.)

[szepeviktor]

can we just do:

.* export-ignore

I do not dare to jump into an empty pool.

Explicit Viktor 🙃

[szepeviktor]

Glad to contribute.

[szepeviktor]

@mindplay-dk You can run a check for exported files in CI.

https://github.com/szepeviktor/byte-level-care/blob/35d9aba1592edae4450db8c97a4c2c9eaa46ba79/.github/workflows/reusable-integrity.yml#L181-L192