docs: add librewolf (#65)

* docs: add librewolf

* librewolf: add zh.yaml and drop gpg --dearmor

- Add librewolf/zh.yaml so the page is included in the generated site.
- keyring.gpg is already a binary OpenPGP keyring; gpg --dearmor fails
  on it with "no valid OpenPGP data found". Save it directly instead.

Author: yaoge123

librewolf/librewolf.zh.md

@@ -0,0 +1,40 @@
+LibreWolf 是基于 Firefox 的开源桌面浏览器，注重隐私、安全与自由。此处镜像其官方 apt/dnf 软件仓库（amd64、arm64）。
+
+### Debian / Ubuntu 用户
+
+导入 GPG 公钥：
+
+```{ztmpl lang="bash"}
+wget -qO- {{endpoint}}/keyring.gpg | sudo tee /usr/share/keyrings/librewolf.gpg > /dev/null
+```
+
+将以下内容写入 `/etc/apt/sources.list.d/librewolf.list`：
+
+```{ztmpl lang="properties" path="/etc/apt/sources.list.d/librewolf.list"}
+deb [signed-by=/usr/share/keyrings/librewolf.gpg] {{endpoint}} librewolf main
+```
+
+然后执行：
+
+```bash
+sudo apt update
+sudo apt install librewolf
+```
+
+### RHEL / Fedora 用户
+
+新建 `/etc/yum.repos.d/librewolf.repo`，内容如下：
+
+```{ztmpl lang="ini" path="/etc/yum.repos.d/librewolf.repo"}
+[librewolf]
+name=LibreWolf Software Repository
+baseurl={{endpoint}}
+gpgcheck=1
+repo_gpgcheck=1
+gpgkey={{endpoint}}/pubkey.gpg
+enabled=1
+```
+
+然后执行 `sudo dnf install librewolf`。
+
+参考文档：https://librewolf.net/installation/

librewolf/zh.yaml

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+_: LibreWolf 软件仓库
+block:
+- librewolf