Add how-to for learn

Author: jondy

pyarmor/learn/zh/how-to.rst

@@ -0,0 +1,22 @@
+==================
+ 常见问题处理方式
+==================
+
+.. contents:: 目录
+   :depth: 2
+   :local:
+   :backlinks: top
+
+.. highlight:: console
+
+如何选择许可证
+==============
+
+如何使用许可证
+==============
+
+如何解决加密过程中问题
+======================
+
+如何解决运行加密脚本时的错误
+============================

pyarmor/learn/zh/index.rst

@@ -3,7 +3,16 @@
    You can adapt this file completely to your liking, but it should at least
    contain the root `toctree` directive.
 
-学习 Pyarmor
+目录
+====
+
+.. toctree::
+   :caption: 学习 Pyarmor
+   :name: learndoc
+   :numbered:
+   :maxdepth: 3
+
+   how-to
 
 索引表
 ======