Fixed non-relative URLs, and some grammar (#554)

docs/en/document/README.md

@@ -10,7 +10,7 @@ sidebar: auto
 
 Xray supports various platforms, and you can get various versions of Xray from various sources and methods.
 
-Please click [How to Download and Install Xray](./install.md) to get Xray
+Please click [How to Download and Install Xray](./install.md) to get Xray.
 
 ## Configure and Run
 
@@ -26,15 +26,15 @@ Please click [Command Parameters for Xray](./command.md) to view more commands a
 
 ## Improve Documents
 
-If you're interested, please click [Documents](./document.md) to help us improve the documents, or click the`Help us improve this page!`
+If you're interested, please click [Documents](./document.md) to help us improve the documents, or click the `Help us improve this page!`
 
 We are very grateful to every Contributor for their contribution! You guys make Project X even stronger!
 
 ## Beginner Tutorial
 
-A easy tutorial for beginner.
+An easy tutorial for beginner.
 
-Please click [小小白白话文](./level-0/) to view it.
+Please click [Beginner Tutorial](./level-0/) to view it.
 
 ## Getting Started Tips
 

docs/en/document/install.md

@@ -22,7 +22,7 @@ Download the compressed package of the corresponding platform, and use it after
 Xray provides two verification methods:
 
 - SHA1/SHA256 digest of the ZIP archive
-- Reproducible build: Please refer to [Compile Xray](https://xtls.github.io/development/intro/compile.html)
+- Reproducible build: Please refer to [Compile Xray](../development/intro/compile.html)
 
 ## Install on Windows
 

docs/en/document/level-2/nginx_or_haproxy_tls_tunnel.md

@@ -36,7 +36,7 @@ xray_client ---tcp--- nginx_client ---HTTPS--- nginx_sever ---tcp--- xray_server
 
 服务端加入如下配置
 
-服务器申请证书不再赘述，参考[白话文](https://xtls.github.io/document/level-0/ch06-certificates.html)
+服务器申请证书不再赘述，参考[白话文](../level-0/ch06-certificates.md)
 
 ```
 stream {