feat: add GetProcessInfo for system package

docs/api/packages/system.md

@@ -31,6 +31,11 @@ import (
 -   [CompareOsEnv](#CompareOsEnv)
 -   [ExecCommand](#ExecCommand)
 -   [GetOsBits](#GetOsBits)
+-   [StartProcess](#StartProcess)
+-   [StopProcess](#StopProcess)
+-   [KillProcess](#KillProcess)
+-   [GetProcessInfo](#GetProcessInfo)
+
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -248,7 +253,7 @@ func main() {
 
 ```go
 type (
-	Option func(*exec.Cmd)
+    Option func(*exec.Cmd)
 )
 func ExecCommand(command string, opts ...Option) (stdout, stderr string, err error)
 ```
@@ -403,4 +408,37 @@ func main() {
     // Output:
     // <nil>
 }
+```
+
+### <span id="GetProcessInfo">GetProcessInfo</span>
+
+<p>根据进程id获取进程信息。</p>
+
+<b>函数签名:</b>
+
+```go
+func GetProcessInfo(pid int) (*ProcessInfo, error)
+```
+
+<b>示例:<span style="float:right;display:inline-block">[运行](todo)</span></b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/system"
+)
+
+func main() {
+    pid, err := system.StartProcess("ls", "-a")
+    if err != nil {
+        return
+    }
+
+    processInfo, err := system.GetProcessInfo(pid)
+    if err != nil {
+        return
+    }
+
+    fmt.Println(processInfo)
+}
 ```