docs: regular minor updates (#101)

Author: YDX-2147483647

main.typ

@@ -390,6 +390,39 @@ $ f(x) = y "（定义8）" $
   zh: [这一问题算作 Basic，因为`gb-7714-2015-numeric`样式的引用采用上标。],
 )
 
+=== #bbl(
+  en: [KaiTi and Noto Serif CJK are misaligned in sub/superscripts],
+  zh: [在上下标中，楷体与思源宋体对不齐],
+) <mix-super-metric>
+
+#level.ok
+#issue("typst#8090", closed: true)
+#pull("typst#8095", merged: true)
+// TODO: Link to typst.app/docs when Typst v0.15 is released.
+
+#babel(
+  en: [KaiTi (aka. 中易楷体, 楷体, simkai) and Noto Serif CJK (思源宋体) are two common fonts. They set incompatible metrics for superscripts and subscripts, resulting in misalignment when used together.],
+  zh: [KaiTi（又名“中易楷体”、楷体、simkai）和 Noto Serif CJK（思源宋体）是两种常见字体。它们设置的上下标度量信息不兼容，导致混合使用时对不齐。],
+)
+
+```example-page
+>>> #set par(leading: 1em) // for displaying superscripts
+#set text(font: "Noto Serif CJK SC")
+#show emph: set text(font: "KaiTi")
+
+>>> Current: \
+标#super[字_词_]
+
+>>> Expected: \
+>>> #set super(baseline: -0.5em, size: 0.6em)
+>>> 标#super[字_词_]
+```
+
+#babel(
+  en: [This affects Chinese particularly, because switching from Song (Serif) to Kai is a common way to express emphasis. However, this issue is still marked as OK. After all, it is straightforward to fix, and superscripts and subscripts rarely use emphasis.],
+  zh: [中文特别受此影响，因为从宋体切换为楷体是表达强调的常见手段。不过这一问题仍算作 OK，毕竟它很容易修复，而且上下标很少需要强调。],
+)
+
 === #bbl(
   en: [Unable to infer the writing script across elements, making `locl` sometimes ineffective],
   zh: [无法跨越元素推断文字种类，导致`locl`特性有时失效],

scripts/download_fonts.sh

@@ -22,8 +22,9 @@ if ! typst fonts --font-path . | rg --quiet '^Source Han Serif SC VF$'; then
   curl --location --remote-name https://mirrors.cernet.edu.cn/adobe-fonts/source-han-serif/Variable/OTF/SourceHanSerifSC-VF.otf
 fi
 
-# A specific version of SimSun
-if ! typst fonts --font-path . | rg --quiet '^SimSun$'; then
+# KaiTi and a specific version of SimSun
+if ! typst fonts --font-path . | rg --quiet '^KaiTi$' || \
+   ! typst fonts --font-path . | rg --quiet '^SimSun$'; then
   curl --location --remote-name https://github.com/typst-doc-cn/guide/releases/download/files/fonts.7z
   7z x fonts.7z -ofonts
   rm fonts.7z