Update documentation for Bellsoft Liberica NIK usage

Closes gh-1357

Author: sdeleuze

spring-native-docs/src/main/asciidoc/attributes.adoc

@@ -7,7 +7,7 @@
 
 :buildpacks: https://buildpacks.io/
 :buildpacks-docs: {buildpacks}/docs
-:buildpacks-java-native-image-version: 5.5.0
+:buildpacks-java-native-image-version: 7.1.0
 
 :paketo: https://paketo.io/
 :paketo-docs: {paketo}/docs

spring-native-docs/src/main/asciidoc/getting-started-buildpacks.adoc

@@ -144,6 +144,7 @@ The plugin provides a number of options to customize the transformations, see <<
 Spring Boot's {spring-boot-docs}/html/spring-boot-features.html#boot-features-container-images-buildpacks[Cloud Native Buildpacks support] lets you build a container for your Spring Boot application.
 The https://github.com/paketo-buildpacks/native-image[native image buildpack] can be enabled using the `BP_NATIVE_IMAGE` environment variable as follows:
 
+NOTE: As of Spring Native 0.11, https://bell-sw.com/pages/liberica-native-image-kit/[Liberica Native Image Kit] (NIK) is the `native-image` compiler distribution used by default with Buildpacks.
 
 [source,xml,subs="attributes,verbatim",role="primary"]
 .Maven

spring-native-docs/src/main/asciidoc/getting-started-native-build-tools.adoc

@@ -10,18 +10,19 @@ This is a practical guide that uses the https://spring.io/guides/gs/rest-service
 A number of {graalvm-native-docs}/#prerequisites[prerequisites] are required before installing the GraalVM `native-image` compiler.
 You then need a local installation of the native image compiler.
 
+There are various distributions of the `native-image` compiler available, here we focus on those 2 ones:
+
+* https://www.graalvm.org/[GraalVM] CE based on the https://github.com/oracle/graal[GraalVM open-source repository] and LabsJDK
+* Bellsoft https://bell-sw.com/pages/liberica-native-image-kit/[Liberica Native Image Kit] (NIK) based on the https://github.com/oracle/graal[GraalVM open-source repository] and Liberica JDK
+
 To install the native image compiler on MacOS or Linux, we recommend using https://sdkman.io/[SDKMAN]:
 
 * https://sdkman.io/install[Install SDKMAN].
-* Install GraalVM with `sdk install java {graalvm-version}.r11-grl` for Java 11.
-* Make sure to use the newly installed JDK with `sdk use java {graalvm-version}.r11-grl`.
+* Install a GraalVM native-image distribution, either GraalVM CE (`grl` suffix) or Bellsoft Liberica NIK (`nik` suffix), here we go with Liberica NIK Java 11 variant: `sdk install java {graalvm-version}.r11-nik`
+* Make sure to use the newly installed JDK with `sdk use java {graalvm-version}.r11-nik`
 * Run `gu install native-image` to bring in the native-image extensions to the JDK.
 
-Alternatively or if you are on Microsoft Windows, you can manually install GraalVM builds as follows:
-
-* Download https://www.graalvm.org/downloads/[GraalVM {graalvm-version}].
-* Set `JAVA_HOME` and `PATH` appropriately.
-* Run `gu install native-image` to bring in the native-image extensions to the JDK.
+Alternatively or if you are on Microsoft Windows, you can manually install builds from https://www.graalvm.org/downloads/[GraalVM] or https://bell-sw.com/pages/downloads/native-image-kit/[Liberica NIK]. Don't forget to set `JAVA_HOME` / `PATH` appropriately if needed and to run `gu install native-image` to bring in the native-image extensions.
 
 ==== Sample Project Setup