Merge branch 'canary' into master (#711)

* refactor(i18n): simplify the structure of the translation file

* chore: prepare repository for v4.0.0-alpha

* chore: modify go.mod to v4

* refactor: migrate theme configuration to TOML

* fix: exampleSite not using correct theme

* feat: add favicon from assets folder

* refactor: drop linear grandient background feature

remove node-vibrant from dependencies

* feat: use Hugo's code block render hook to implement code copy button

Now it can have i18n support

* refactor: delete color.ts

* refactor: delete Emoji support post from example site

* refactor: drop support for `hidden` field in front matter

* feat: upgrade to PhotoSwipe v5

* chore: bump the required hugo version to 0.100.0

* refactor: remove PhotoSwipe from external.yaml

* fix: extra margin in search result

* fix: incorrect markdown heading level in example site

* refactor: remove some usages of `default` in template

No longer needed thanks to Hugo's configuration merge

* fix: one line codeblock style in firefox

closes https://github.com/CaiJimmy/hugo-theme-stack/issues/564

* feat: add style to new codeblock

* feat: i18n support for codeblock copy text

* fix(menu): jitter when closing menu

It's caused by flexbox gap property, which can't animate

* fix(search): long text overflows under the Search icon

closes https://github.com/CaiJimmy/hugo-theme-stack/issues/515

layouts/_default/list.html

@@ -25,7 +25,7 @@
                         {{- $Width := $image.resource.Width -}}
                         {{- $Height := $image.resource.Height -}}
     
-                        {{- if (default true .Page.Site.Params.imageProcessing.cover.enabled) -}}
+                        {{- if .Page.Site.Params.imageProcessing.cover.enabled -}}
                             {{- $thumbnail := $image.resource.Fill "120x120" -}}
                             {{- $Permalink = $thumbnail.RelPermalink -}}
                             {{- $Width = $thumbnail.Width -}}