fix typos - #1237

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache@v3, actions/setup-node@v3, wenkokke/setup-agda@v2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Prefer to use the native <ul> element

Prefer to use the native <li> element

Prefer to use the native <ul> element

Prefer to use the native <li> element

Prefer to use the native <li> element

Prefer to use the native <li> element

Prefer to use the native <li> element

Prefer to use the native <ul> element

Duplicate ID "cb1-1"

Duplicate ID "cb1"