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/_markup/render-codeblock.html

@@ -0,0 +1,20 @@
+{{- $class := .Attributes.class | default ""    -}}
+{{- $lang  := .Attributes.lang  | default .Type -}}
+<div class="codeblock">
+    <header>
+        <span class="codeblock-lang">{{ $lang }}</span>
+        <button 
+            class="codeblock-copy"
+            data-id="codeblock-id-{{ .Ordinal }}"
+            data-copied-text="{{ T `article.codeblock.copied` }}"
+        >
+            {{ T `article.codeblock.copy` }}
+        </button>
+    </header>
+    <code id="codeblock-id-{{ .Ordinal }}" style="display:none;">{{- .Inner -}}</code>
+    {{- if transform.CanHighlight $lang -}}
+    <div class="{{ $class }}">{{- highlight .Inner $lang -}}</div>
+    {{- else -}}
+    <pre><code class="{{ $class }}">{{- .Inner -}}</code></pre>
+    {{- end -}}
+</div>

layouts/_default/_markup/render-image.html

@@ -17,7 +17,7 @@
 		{{- $Height = $image.Height -}}
 		{{- $galleryImage = true -}}
 
-		{{- if (default true .Page.Site.Params.imageProcessing.content.enabled) -}}
+		{{- if .Page.Site.Params.imageProcessing.content.enabled -}}
 			{{- $small := $image.Resize `480x` -}}
 			{{- $big := $image.Resize `1024x` -}}
 			{{- $Srcset = printf `%s 480w, %s 1024w` $small.RelPermalink $big.RelPermalink -}}