backport #26739

* Create issue template using new format

This issue template has been based off of the current issue creation workflow defined in the ISSUE_TEMPLATE.md file
This commit allows for that issue template (which is a legacy method of creating an issue) to be deleted

* Delete old issue template file

This commit deletes the old issue template file, as it is both legacy and replaced by ISSUE_TEMPLATE/issue.yaml

* Adjust file upload and remove code of conduct checkbox

* Block blank issue creation

* Update feedback

Removed most requirements
Updated prompt to include instruction to state whether using try.gitea.io
Added default value to Gitea version

* Create Feature Request issue form

* Update and rename issue.yaml to bug-report.yaml

* Enable blank issue creation

Co-authored-by: a101211279 <1012112796@qq.com>

* Update config.yaml

* Remove default & placeholder from Gitea version

* Create issue template in .gitea directory

* Add relevant bug report message to feature request

* Adjust name to remove banner

There is a banner that tells you to create a config.yml when you already have a config.yaml
Renaming the file stops this from occurring.

* Add UI bug report form

* Remove unnecessary question

Co-authored-by: a101211279 <1012112796@qq.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Lauris BH <lauris@nix.lv>

* chore: are you using Gitea behind CloudFlare

since more often than not CF appears to serve stale cache and cause
troubles, I'd argue it might be helpful to ask about it in this here
issue template

* implement suggestion: change question to comment

* as per @techknowlogick's suggestion

* chore: edit comment

* implement @mrsdizzie's suggestion
* as the comment grows, rather span multiple lines
* Gitea --> gitea to match case used in the rest of the template

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

Almost every use of "Not relevant" I see is the opposite -- it is relevant to have an example on try.gitea.io and often we can't do anything until the user provides one. Remove the not-relevant option so people have to decide yes/no if they are going to attempt to reproduce it which will hopefully encourage them to do so in simple cases. 

For actual not-relevant issues No should be a fine answer as well as it would be clear to us when you can't reproduce an example there.

Hopefully this will encourage more examples when people file issues which would lead to quicker fixes.

For `UI`-bugs we usually require a Screenshot to debug it :wink:

* Update example install url from try.gogs.io to try.gitea.io

* Ask if issue can be reproduced on try.gitea.io

* Link try.gitea.io to the README