added doc

README.md

@@ -3,6 +3,7 @@
 ## Memos
 
 * [Installation](https://git.netig.net/netig/chimera-linux/src/branch/main/installation.md)
+* [Mirrors](https://git.netig.net/netig/chimera-linux/src/branch/main/mirrors.md)
 * [Tips and tricks](https://git.netig.net/netig/chimera-linux/src/branch/main/tips-and-tricks.md)
 * [Containers](https://git.netig.net/netig/chimera-linux/src/branch/main/containers.md)
 * [UFW configuration](https://git.netig.net/netig/chimera-linux/src/branch/main/ufw-config.md)

mirrors

@@ -0,0 +1,15 @@
+The system comes preconfigured with a repository. If this repository
+is too slow for you, you might want to switch to a different mirror.
+
+This may be done by editing the file `/etc/apk/repositories.d/00-repo-main.list`.
+
+The repositories take the the form `URL/current/CATEGORY` where `URL`
+is the mirror base URL, and `category` is one of `main`, `main/debug`,
+`user`, `user/debug`.
+
+The following mirrors are available:
+
+* [https://repo.chimera-linux.org](https://repo.chimera-linux.org) (hosted by the project, Czechia)
+* [https://chimera.sakamoto.pl](https://chimera.sakamoto.pl) (hosted by sdomi, Poland)
+* [https://au.mirror.7bit.org/chimera](https://au.mirror.7bit.org/chimera) (hosted by wezm, Australia)
+* [https://chimera.netig.net](https://chimera.netig.net) (hosted by netig, Sweden)