v0.3.0

84a887d Bump version to 0.3.0
6f0f62f Lua template: Add Http Variables
38688ef new function: uh_foreach_var()
f096369 optimize code
1873edb Fix bug: uh_get_var()
90f38a6 Lua template: Improve and optimize
93705e0 Fix doc format
2ab93c9 Lua template: Optimize code
52f6309 Lua template: Add the headers variable
e5e3fcc template.c: Convert the document format to UNIX format.
9fea273 Update README_ZH.md
d38f1d1 Add test file for Lua template
e4d8ce1 Support Lua template
4d27dc4 Optimize code
6bc0e5f new function: uh_get_method(), uh_get_method_str()
519559c uh_get_con_sock(): New function
cb5cfff Update README
84c0e8e Update README
3cf95b2 Optimizing performance by less memory allocation times
7da483c uh_send_head: fix wrong description
e6ab115 str.h: Convert its document format to UNIX
564a545 Fix typo
5200f78 Update README
3a89216 Update README.md
070c27e Update CONTRIBUTING.md