confused about the documentation [important]

I think there do not have a clear describe regard to seata component and their respective configration.
Yea, you guys wrote a documentation but it just describe every option's mean.
Yea, you guys impletment various of config and registy center but it's not clearly about their's usage.
But I do not recomment wrote a documentaion all in one.

Let's have a look about what happen
Fristly I download a seata server package and found there have 2 files about the configruation.
One is conf/application.yaml which one I think is a configuration for seata sever seems like our springcloud's application.yml.
One is script/config-center/config.txt which one is refer to [seata offical documentation](https://seata.io/zh-cn/docs/user/configurations.html)

question 1:
参数同步到配置中心使用demo
I did it.
And then It looks strange. My first impression of this is something maybe really wrong. but ,I don't know.
question 2:
There do not have a documentation about application.yaml Just have a example file .
`seata.config.nacos.data-id` for what?
Does this prove someting about question one ,I don't know.
```
seata:
config:
# support: nacos 、 consul 、 apollo 、 zk 、 etcd3
type: file
nacos:
server-addr: 127.0.0.1:8848
namespace:
group: SEATA_GROUP
username:
password:
context-path:
##if use MSE Nacos with auth, mutex with username/password attribute
#access-key: ""
#secret-key: ""
data-id: seataServer.properties
```
I'm still confused about where this configuration should be placed,and when they will be loaded and use.

Start by comparing conf/application.yaml with script/config-center/config.txt and the linked configuration documentation. Trace the documented role of seata.config.nacos.data-id, where the application.yaml settings are placed, and when each configuration source is loaded. Done means the component, configuration-center usage, file locations, loading order, and relationship between the two files are explained clearly.

Written by the indexing model from the issue text.