docs(install): use material admonition instead of unicode caution

- use [admonitions](https://squidfunk.github.io/mkdocs-material/reference/admonitions/) that come with the material theme
  - instead of a unicode caution sign

- be more specific in the notes as well
  - using a remote base is not inherently "dangerous" as the previous sentence said without elaboration
    - instead specify that you should use a full hash when using a remote base
    - and add a link to Kustomize's remote base docs
  - similarly in the second note, specify what "tip" means
    - and specify what you should do instead of using `latest`

Signed-off-by: Anton Gilgur <agilgur5@gmail.com>

docs/installation.md

@@ -14,9 +14,12 @@ To install Argo Workflows, navigate to the [releases page](https://github.com/ar
 
 You can use Kustomize to patch your preferred [configurations](managed-namespace.md) on top of the base manifest.
 
-⚠️ If you are using GitOps, never use Kustomize remote base: this is dangerous. Instead, copy the manifests into your Git repo.
+!!! Note "Use a full hash"
+    If you are using a [remote base](https://github.com/kubernetes-sigs/kustomize/blob/ab519fdc13ded9875e42d70ac8a5b1b9023a2dbb/examples/remoteBuild.md) with Kustomize, you should specify a full commit hash, for example `?ref=960af331a8c0a3f2e263c8b90f1daf4303816ba8`.
 
-⚠️ `latest` is tip, not stable. Never run it in production.
+!!! Warning "`latest` vs stable"
+    `latest` is the tip of the `main` branch and may not be stable.
+    In production, you should use a specific release version.
 
 #### Argo Workflows Helm Chart