docs: Use versioned installation manifests in install docs (#233)

* docs: Use versioned installation manifests in install docs

Signed-off-by: jannfis <[email protected]>

* docs: Use versioned installation manifests in install instructions

Signed-off-by: jannfis <[email protected]>

Author: jannfis

.github/actions/spelling/allow.txt

@@ -72,6 +72,7 @@ gh
 ghcr
 githash
 github
+githubusercontent
 GOARCH
 goimports
 golang

docs/install/start.md

@@ -85,7 +85,7 @@ Argo CD is running. Don't worry, without any configuration, it will not start me
 ### Apply the installation manifests
 
 ```shell
-kubectl apply -n argocd -f manifests/install.yaml
+kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj-labs/argocd-image-updater/stable/manifests/install.yaml
 ```
 
 !!!note "A word on high availability"