Don't recommend .npmrc proxy configuration (#18319)

* Don't recommend .npmrc proxy configuration

* Don't recommend .npmrc proxy configuration

* Remove trailing / from registry urls

Co-authored-by: jmarlena <6732600+jmarlena@users.noreply.github.com>

Author: jcansdale

content/packages/guides/configuring-npm-for-use-with-github-packages.md

@@ -192,18 +192,16 @@ If your instance has subdomain isolation enabled:
 {% endif %}
 
 ```shell
-registry=https://{% if currentVersion == "free-pro-team@latest" %}npm.pkg.github.com{% else %}npm.<em>HOSTNAME</em>{% endif %}/<em>OWNER</em>
-@<em>OWNER</em>:registry=https://{% if currentVersion == "free-pro-team@latest" %}npm.pkg.github.com{% else %}npm.<em>HOSTNAME</em>/{% endif %}
-@<em>OWNER</em>:registry=https://{% if currentVersion == "free-pro-team@latest" %}npm.pkg.github.com{% else %}npm.<em>HOSTNAME</em>/{% endif %}
+@<em>OWNER</em>:registry=https://{% if currentVersion == "free-pro-team@latest" %}npm.pkg.github.com{% else %}npm.<em>HOSTNAME</em>{% endif %}
+@<em>OWNER</em>:registry=https://{% if currentVersion == "free-pro-team@latest" %}npm.pkg.github.com{% else %}npm.<em>HOSTNAME</em>{% endif %}
 ```
 
 {% if enterpriseServerVersions contains currentVersion %}
 If your instance has subdomain isolation disabled:
 
 ```shell
-registry=https://<em>HOSTNAME</em>/_registry/npm/<em>OWNER</em>
-@<em>OWNER</em>:registry=https://<em>HOSTNAME</em>/_registry/npm/
-@<em>OWNER</em>:registry=https://<em>HOSTNAME</em>/_registry/npm/
+@<em>OWNER</em>:registry=https://<em>HOSTNAME</em>/_registry/npm
+@<em>OWNER</em>:registry=https://<em>HOSTNAME</em>/_registry/npm
 ```
 {% endif %}
 

data/reusables/package_registry/create-npmrc-owner-step.md

@@ -2,15 +2,15 @@
 
 {% if currentVersion == "free-pro-team@latest" %}
   ```shell
-registry=https://npm.pkg.github.com/<em>OWNER</em>
+  @<em>OWNER</em>:registry=https://npm.pkg.github.com
   ```
 {% else %}
   If subdomain isolation is enabled:
   ```shell
-  registry=https://npm.<em>HOSTNAME</em>/<em>OWNER</em>
+  @<em>OWNER</em>:registry=https://npm.<em>HOSTNAME</em>
   ```
   If subdomain isolation is disabled:
   ```shell
-  https://<em>HOSTNAME</em>/_registry/npm/<em>OWNER</em>
+  @<em>OWNER</em>:registry=https://<em>HOSTNAME</em>/_registry/npm
   ```
 {% endif %}