Add readme for ksp (#1233)

Author: IceBlizz6

querydsl-tooling/querydsl-ksp-codegen/readme.md

@@ -0,0 +1,68 @@
+# KSP for QueryDSL
+Provides a lightweight and efficient way to generate `Q` classes for QueryDSL in Kotlin projects.  
+Supports only jakarta annotations.
+
+Let us know if you want support for other annotations.
+
+## Setup
+
+### Gradle
+Add the KSP plugin and dependency for the processor in your `build.gradle.kts`
+
+```kotlin
+plugins {
+    kotlin("jvm") version "2.1.21"
+    id("com.google.devtools.ksp") version "2.1.21-2.0.2"
+	kotlin("plugin.jpa")
+	kotlin("plugin.serialization")
+}
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	implementation("jakarta.persistence:jakarta.persistence-api:${jpaVersion}")
+	implementation("io.github.openfeign.querydsl:querydsl-jpa:${querydslVersion}")
+	ksp("io.github.openfeign.querydsl:querydsl-ksp-codegen:${querydslVersion}")
+}
+```
+
+And it may be necessary to [make your IDE aware of KSP generated code](https://kotlinlang.org/docs/ksp-quickstart.html#make-ide-aware-of-generated-code)
+
+```kotlin
+kotlin {
+    sourceSets.main {
+        kotlin.srcDir("build/generated/ksp/main/kotlin")
+    }
+    sourceSets.test {
+        kotlin.srcDir("build/generated/ksp/test/kotlin")
+    }
+}
+```
+
+### Settings (all optional)
+
+| Name           |  Type                       | Default       | Description |
+|:---------------|:----------------------------|:--------------|:------|
+|enable          |Boolean                      |true           |Set to false will disable processing|
+|indent          |String                       |" " (4 spaces)|Indent used in generated code files|
+|prefix          |String                       |"Q"            |Prefix applied to generated classes|
+|suffix          |String                       |""             |Suffix applied to generated classes|
+|packageSuffix   |String                       |""             |Suffix applied to package name of generated classes|
+|excludedPackages|String (comma separated list)|""             |List of packages that will be skipped in processing|
+|excludedClasses |String (comma separated list)|""             |List of classes that will not be processed|
+|includedPackages|String (comma separated list)|""             |List of packages included, empty means it will include everything|
+|includedClasses |String (comma separated list)|""             |List of classes included, empty means it will include all|
+
+Settings must be prefixed with 'querydsl.'
+
+Add into your `build.gradle.kts` to configure.
+
+```kotlin
+// Example
+ksp {
+    arg("querydsl.prefix", "QQ")
+    arg("querydsl.excludedPackages", "com.example, com.sample")
+}
+```