Update FAQ according to #98, #99.

README.md

@@ -162,6 +162,15 @@ For the personal configurations, you could put to `~/.emacs.d/custom-post.el`.
     `(setq all-the-icons-color-icons nil)` to disable. Please refer to
     [all-the-icons.el](https://github.com/domtronn/all-the-icons.el) for details.
 
+1. The packages cannot be installed, what should I do?
+
+   Generally it's due to connection issue. Please refer to
+   [#98](https://github.com/seagle0128/.emacs.d/issues/98).
+   - `M-x package-refresh-contents` and try again.
+   - `(setq gnutls-algorithm-priority "NORMAL:-VERS-TLS1.3")`.
+   - Use other mirror of elpa.
+   - Change another network to retry.
+
 1. How to search Chinese via pinyin?
 
     In Emacs, `C-s !`. If you just want to search `!`, use `C-s \!`.