Add readme/docs snippers for nonroot operation

roles/generate-jenkins/templates/DOCUMENTATION.j2

@@ -40,6 +40,10 @@ title: {{ project_name }}
 {% if readonly_supported is defined and readonly_supported %}
 {% include "README_SNIPPETS/READONLY.j2" | trim %}
 
+{% endif %}
+{% if nonroot_supported is defined and nonroot_supported %}
+{% include "README_SNIPPETS/NONROOT.j2" | trim %}
+
 {% endif %}
 {% if ["CI_SSL='true'", "CI_SSL= 'true'" ,"CI_SSL = 'true'"]|select("in", repo_vars) %}
 {% include "README_SNIPPETS/STRICT_PROXY.j2" | trim %}

roles/generate-jenkins/templates/README.j2

@@ -39,6 +39,10 @@
 {% if readonly_supported is defined and readonly_supported %}
 {% include "README_SNIPPETS/READONLY.j2" | trim %}
 
+{% endif %}
+{% if nonroot_supported is defined and nonroot_supported %}
+{% include "README_SNIPPETS/NONROOT.j2" | trim %}
+
 {% endif %}
 {% if ["CI_SSL='true'", "CI_SSL= 'true'" ,"CI_SSL = 'true'"]|select("in", repo_vars) %}
 {% include "README_SNIPPETS/STRICT_PROXY.j2" | trim %}
@@ -146,6 +150,9 @@ Containers are configured using parameters passed at runtime (such as those abov
 {% if readonly_supported is defined and readonly_supported %}
 | `--read-only=true` | Run container with a read-only filesystem. Please [read the docs](https://docs.linuxserver.io/misc/read-only/). |
 {% endif %}
+{% if nonroot_supported is defined and nonroot_supported %}
+| `--user=1000:1000` | Run container with a non-root user. Please [read the docs](https://docs.linuxserver.io/misc/non-root/). |
+{% endif %}
 {% if cap_add_param or opt_cap_add_param or (custom_params is defined and 'sysctl' in (custom_params | map(attribute="name")) ) %}
 
 ### Portainer notice

roles/generate-jenkins/templates/README_SNIPPETS/NONROOT.j2

@@ -0,0 +1,9 @@
+## Non-Root Operation
+
+This image can be run with a non-root user. For details please [read the docs](https://docs.linuxserver.io/misc/non-root/).
+{% if nonroot_message is defined %}
+
+### Caveats
+
+{{ nonroot_message | trim }}
+{% endif %}