correct markdown error

don't use html in markdown files... to make a line break in a bullet list, you use the same indentation as you do with fenced code blocks / images

Author: andrewconnell

docs/spfx/sharepoint-2019-and-subscription-edition-support.md

@@ -48,8 +48,9 @@ Microsoft recommends using the most recent version of the Yeoman generator for t
 
 ### Prepare the environment for SharePoint Framework development
 
-1. Install [Node.js v8.17.0](https://nodejs.org/download/release/v8.17.0/).<br>
-   SPFx v1.4.1 is also supported on Node.js v12 and v14 (v12.18.1 and v14.17.1 to be specific), although there is an incompatible issue [gulp 3 wasn't compatible with Node 12+](https://github.com/gulpjs/gulp/issues/2324). The workaround to resolve this issue is to specify the version of graceful-fs component as 4+. You can create npm-shrinkwrap.json in the root folder of the project and input the following content, and then run “npm install”. Also, you can use package-lock.json to resolve this issue too.
+1. Install [Node.js v8.17.0](https://nodejs.org/download/release/v8.17.0/).
+   
+    SPFx v1.4.1 is also supported on Node.js v12 and v14 (v12.18.1 and v14.17.1 to be specific), although there is an incompatible issue [gulp 3 wasn't compatible with Node 12+](https://github.com/gulpjs/gulp/issues/2324). The workaround to resolve this issue is to specify the version of graceful-fs component as 4+. You can create npm-shrinkwrap.json in the root folder of the project and input the following content, and then run “npm install”. Also, you can use package-lock.json to resolve this issue too.
 
     ```powershell
     {