doc: update

Author: kaiwk

README.md

@@ -6,9 +6,14 @@ LeetCode brings you offer, and now Emacs brings you LeetCode!
 # Installation
 
 - Vanilla Emacs: `package-install` it from melpa directly
-- [Spacemacs](https://github.com/syl20bnr/spacemacs): [leetcode-emacs-layer](https://github.com/anmoljagetia/leetcode-emacs-layer)
+- [Spacemacs](https://github.com/syl20bnr/spacemacs):
+  [leetcode-emacs-layer](https://github.com/anmoljagetia/leetcode-emacs-layer)
 
-LeetCode do not allow third party login, one workaround is restore LeetCode session from local Chrome cookies. By default, this package will install a Python3 package called [my\_cookies](https://github.com/kaiwk/my_cookies), or you can install it manually: `pip3 install my_cookies`.
+LeetCode do not allow third party login, one workaround is restore LeetCode
+session from local Firefox or Chrome cookies. By default, this package will
+install a Python3 package called
+[my\_cookies](https://github.com/kaiwk/my_cookies), or you can install it
+manually: `pip3 install my_cookies`.
 
 ## Manually
 
@@ -18,14 +23,16 @@ LeetCode do not allow third party login, one workaround is restore LeetCode sess
 
 # Configuration
 
-You can set your preferred LeetCode programming language and SQL by setting `leetcode-prefer-language` and `leetcode-prefer-sql`:
+You can set your preferred LeetCode programming language and SQL by setting
+`leetcode-prefer-language` and `leetcode-prefer-sql`:
 
 ```elisp
 (setq leetcode-prefer-language "python3")
 (setq leetcode-prefer-sql "mysql")
 ```
 
-All supported languages can be found in variable `leetcode--prefer-language-suffixes`.
+All supported languages can be found in variable
+`leetcode--prefer-language-suffixes`.
 
 You can save solution by setting `leetcode-save-solutions`:
 
@@ -53,16 +60,18 @@ In leetcode problems list buffer:
 | G      | refresh all data                       |
 | RET    | show current problem description       |
 
-2. Press `<RET>`, show problem description, move cursor to "solve it", press `<RET>` again, start coding!
+2. Press `<RET>`, show problem description, move cursor to "solve it", press
+   `<RET>` again, start coding!
 
-3. After finishing your code, you can edit testcase and execute `leetcode-try` or execute `leetcode-submit`.
+3. After finishing your code, you can edit testcase and execute `leetcode-try`
+   or execute `leetcode-submit`.
 
 ![leetcode-submit](images/leetcode-submit.png)
 
 # Debug
 
 Call `leetcode-toggle-debug`, log will output in `*leetcode-log*` buffer.
 
-# Contribution
+# Contributing
 
 Please submit PR to develop branch.