docs(lb): Add description of Alias Method (#1034)

content/en/docs/kitex/Tutorials/service-governance/loadbalance.md

@@ -11,6 +11,7 @@ Kitex provides these LoadBalancers officially:
 - WeightedRoundRobin
 - InterleavedWeightedRoundRobin (kitex >= v0.7.0)
 - WeightedRandom
+- Alias Method（kitex >= v0.9.0）
 - ConsistentHash
 - Tagging Based
 
@@ -56,6 +57,17 @@ If all instances have the same weights, it uses a purely random implementation t
 ```go
 cli, err := echo.NewClient("echo", client.WithLoadBalancer(loadbalance.NewWeightedRandomBalancer()))
 ```
+
+## Alias Method
+
+LoadBalancer that uses the Alias Method, specifically implementing Vose's Alias Method from [Darts, Dice, and Coins](https://www.keithschwarz.com/darts-dice-coins/).
+
+Generates an alias table in O(n) time, then selects an instance in O(1) time, achieving higher selection efficiency than [WeightedRandom](#weightedrandom).
+
+```go
+cli, err := echo.NewClient("echo", client.WithLoadBalancer(loadbalance.NewWeightedRandomWithAliasMethodBalancer()))
+```
+
 ## ConsistentHash
 
 ### Introduction

content/zh/docs/kitex/Tutorials/service-governance/loadbalance.md

@@ -11,6 +11,7 @@ Kitex 默认提供了以下几种 LoadBalancer：
 - WeightedRoundRobin
 - InterleavedWeightedRoundRobin（kitex >= v0.7.0）
 - WeightedRandom
+- Alias Method（kitex >= v0.9.0）
 - ConsistentHash
 - Tagging Based
 
@@ -57,6 +58,17 @@ cli, err := echo.NewClient("echo", client.WithLoadBalancer(loadbalance.NewInterl
 cli, err := echo.NewClient("echo", client.WithLoadBalancer(loadbalance.NewWeightedRandomBalancer()))
 ```
 
+## Alias Method
+
+使用别名方法的 LoadBalancer ，具体来说实现的是 [Darts, Dice, and Coins](https://www.keithschwarz.com/darts-dice-coins/) 中的 Vose's Alias Method
+
+使用 O(n) 时间生成别名表，之后在 O(1) 时间内选取实例，选取效率比 [WeightedRandom](#weightedrandom) 更高
+
+```go
+cli, err := echo.NewClient("echo", client.WithLoadBalancer(loadbalance.NewWeightedRandomWithAliasMethodBalancer()))
+```
+
+
 ## ConsistentHash
 
 ### 简介