Update encoding of CHANGELOG

[pjaap]

On my end, VSCode always mutates the CHANGELOG.md. Even without changing anything in that file.

I investigated this:

before:

$ file CHANGELOG.md 
CHANGELOG.md: ASCII text, with CRLF, LF line terminators

after opening with VSCode (without doing anything)

$ file CHANGELOG.md 
CHANGELOG.md: ASCII text

Somehow it removes CRLF, LF line terminators ... The file was probably edited with another operating system/strange editor.

Is there any reason to keep this? Otherwise this PR makes it plain ASCII. Then, my VSCode is happy :)
No contents are changed, btw.

[j-fu]

It was initially generated with git-cliff in order to catch up with older commits. I don't intend to use this tool further.

Changing to normal ASCII is ok.

[pjaap]

Ok, thanks for the info.