Add the document for sql-mode of MySQL (#147)

* Add the doc for sql-mode of MySQL

* Fix the index doc

Author: Noah Hanjun Lee

README.md

@@ -7,7 +7,7 @@
 
 ## What is Gitploy?
 
-Gitploy builds the advanced deployment pipelines around [Github Deployments API](https://docs.github.com/en/rest/reference/repos#deployments) in minutes. And also Gitploy provides advanced features, such rollback, approval, and locks.
+Gitploy builds the system around GitHub [deployment API](https://docs.github.com/en/rest/reference/repos#deployments) in minutes. It enables teams or organization to deploy the application with lower risk and faster.
 
 ## Docs and Support
 

docs/concepts/chatops.md

@@ -2,7 +2,7 @@
 
 ChatOps is a term that’s been coined recently to refer to using chat services, such as Slack or Microsoft Teams, to deploy or run some operations. Gitploy also supports Chatops as a helper tool. 
 
-![Slack deploy](../images//slack-deploy.png)
+![Slack deploy](../images/slack-deploy.png)
 
 ## Integration
 

docs/images/gitploy.png

@@ -1,7 +1,8 @@
 # Gitploy
 
-![Gitploy](./images/gitploy.png)
+Gitploy builds the system around GitHub [deployment API](https://docs.github.com/en/rest/reference/repos#deployments) in minutes. It enables teams or organization to deploy the application with lower risk and faster. You can check this [document](./concepts/how-it-work.md) for the detail.
 
 ---
 
-Gitploy helps **you can build the advanced deployment pipeline in minutes**. It enables teams to deploy the application with lower risk and faster when to trigger a deployment. And the pipeline is configured with a simple, easy‑to‑read file that you commit to your git repository.
+![Gitploy](./images/gitploy.png)
+

docs/index.md

@@ -11,11 +11,21 @@ GITPLOY_STORE_DRIVER=mysql
 GITPLOY_STORE_SOURCE=root:password@tcp(1.2.3.4:3306)/gitploy?parseTime=true
 ```
 
+### *⚠️ WARNING*
+
+You have to setting the SQL mode by removing `NO_ZERO_DATE` from the default setting to enable the zero value for the `timestamp` type. 
+
+```
+sql-mode='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION'
+```
+
+To set the SQL mode, you can check the official [document](https://dev.mysql.com/doc/refman/8.0/en/sql-mode.html).
+
 ## Postgres
 
 Gitploy supports postgres on the following 4 versions: `10`, `11`, `12` and `13`. The below example demonstrates postgres database configuration. See the official driver [documentation](https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING) for more connection string details.
 
 ```
 GITPLOY_STORE_DRIVER=postgres
-GITPLOY_STORE_SOURCE=postgres://root:password@1.2.3.4:5432/gitploy?sslmode=disable
+GITPLOY_STORE_SOURCE=root:password@1.2.3.4:5432/gitploy?sslmode=disable
 ```