Correct vim modeline in ChangeLog

[softins]

Short description of changes

Update the vim modeline in ChangeLog to fix vim error and enable syntax highlighting

CHANGELOG: SKIP

Context: Fixes an issue?

The vim modeline that was added to ChangeLog in #2899 is enough to make Github render the file as Markdown, but it results in vim errors when editing the file:

$ vim ChangeLog
"ChangeLog" 2056L, 73367B
Error detected while processing modelines:
line 2056:
E518: Unknown option: -->
Press ENTER or type command to continue

It is because the closing comment tag --> is interpreted by vim as a command. In addition, the syntax=Markdown does not turn on syntax highlighting within vim. For that, set ft=markdown: is needed, and the trailing : prevents the --> from being interpreted by vim.

Does this change need documentation? What needs to be documented and how?

Status of this Pull Request

Ready to merge

What is missing until this pull request can be merged?

Nothing

Checklist

• I've verified that this Pull Request follows the general code principles
• I tested my code and it does what I want
• My code follows the style guide
• I waited some time after this Pull Request was opened and all GitHub checks completed without errors.
• I've filled all the content above

[ann0see]

Can confirm that it works. Thanks.

[pljones]

Maybe use the full form of the setting - filetype - rather than an abbreviation?

[pljones]

(Could do with filetype=cfg in Jamulus.pro, too.)

[softins]

(Could do with filetype=cfg in Jamulus.pro, too.)

Good idea. Though I'll do that separately from this bug fix.

[softins]

(Could do with filetype=cfg in Jamulus.pro, too.)

cfg is an ok generic filetype for Jamulus.pro, but better is to install the syntax and filetype detect files from https://github.com/artoj/qmake-syntax-vim