add conf how to write

Author: mokusen

conf.md

@@ -0,0 +1,15 @@
+# Confの位置
+
+## MySQL5.7
+### mysql-community-server
+- `/etc/my.cnf`
+
+### docker
+- `etc/mysql/mysql.conf.d/mysqld.cnf`と`etc/mysql/conf.d/mysql.cnf`
+
+## MySQL8.0
+### mysql-community-server
+- `/etc/my.cnf`
+
+### Docker版
+- `/etc/my.cnf`と`etc/mysql/conf.d/mysql.cnf`