plugins: Always install plugins with --no-save

The npm CLI can get confused if `package.json` or `package-lock.json`
exist.

.github/workflows/backend-tests.yml

@@ -58,7 +58,7 @@ jobs:
 
     - name: Install Etherpad plugins
       run: >
-        npm install
+        npm install --no-save
         ep_align
         ep_author_hover
         ep_cursortrace

.github/workflows/frontend-admin-tests.yml

@@ -28,7 +28,7 @@ jobs:
 
       # We intentionally install a much old ep_align version to test update minor versions
     - name: Install etherpad plugins
-      run: npm install ep_align@0.2.27
+      run: npm install --no-save ep_align@0.2.27
 
       # Nuke plugin tests
     - name: Install etherpad plugins

.github/workflows/frontend-tests.yml

@@ -65,7 +65,7 @@ jobs:
 
     - name: Install Etherpad plugins
       run: >
-        npm install
+        npm install --no-save
         ep_align
         ep_author_hover
         ep_cursortrace

.github/workflows/load-test.yml

@@ -52,7 +52,7 @@ jobs:
 
     - name: Install etherpad plugins
       run: >
-        npm install
+        npm install --no-save
         ep_align
         ep_author_hover
         ep_cursortrace

.travis.yml

@@ -29,7 +29,7 @@ _install_libreoffice: &install_libreoffice >-
   sudo apt-get -y install libreoffice libreoffice-pdfimport
 
 _install_plugins: &install_plugins >-
-  npm install
+  npm install --no-save
   ep_align
   ep_author_hover
   ep_cursortrace

README.md

@@ -105,7 +105,7 @@ Etherpad is very customizable through plugins. Instructions for installing theme
 Run the following command in your Etherpad folder to get all of the features visible in the demo gif:
 
 ```
-npm install ep_headings2 ep_markdown ep_comments_page ep_align ep_font_color ep_webrtc ep_embedded_hyperlinks2
+npm install --no-save ep_headings2 ep_markdown ep_comments_page ep_align ep_font_color ep_webrtc ep_embedded_hyperlinks2
 ```
 
 ## Customize the style with skin variants

doc/plugins.md

@@ -7,8 +7,8 @@ execute its own functionality based on these events.
 Publicly available plugins can be found in the npm registry (see
 <https://npmjs.org>). Etherpad's naming convention for plugins is to prefix your
 plugins with `ep_`. So, e.g. it's `ep_flubberworms`. Thus you can install
-plugins from npm, using `npm install ep_flubberworm` in Etherpad's root
+plugins from npm, using `npm install --no-save ep_flubberworm` in Etherpad's
-directory.
+root directory.
 
 You can also browse to `http://yourEtherpadInstan.ce/admin/plugins`, which will
 list all installed plugins and those available on npm. It even provides

src/bin/plugins/lib/README.md

@@ -7,7 +7,10 @@ Explain what your plugin does and who it's useful for.
 ![screenshot](https://user-images.githubusercontent.com/220864/99979953-97841d80-2d9f-11eb-9782-5f65817c58f4.PNG)
 
 ## Installing
-npm install [plugin_name]
+
+```
+npm install --no-save [plugin_name]
+```
 
 or Use the Etherpad ``/admin`` interface.