doc: fix typographical issues

PR-URL: #23970
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

doc/api/synopsis.md

@@ -14,7 +14,7 @@ An example of a [web server][] written with Node.js which responds with
 
 Commands displayed in this document are shown starting with `$` or `>`
 to replicate how they would appear in a user's terminal.
-Do not include the `$` and `>` character they are there to
+Do not include the `$` and `>` characters. They are there to
 indicate the start of each command.
 
 There are many tutorials and examples that follow this
@@ -27,8 +27,8 @@ the output of the previous command.
 Firstly, make sure to have downloaded and installed Node.js.
 See [this guide][] for further install information.
 
-Now, create an empty project folder called `projects`, navigate into it:
-Project folder can be named base on user's current project title but
+Now, create an empty project folder called `projects`, then navigate into it.
+The project folder can be named based on the user's current project title, but
 this example will use `projects` as the project folder.
 
 Linux and Mac:
@@ -60,7 +60,7 @@ hyphens (`-`) or underscores (`_`) to separate
  multiple words in filenames.
 
 Open `hello-world.js` in any preferred text editor and
-paste in the following content.
+paste in the following content:
 
 ```js
 const http = require('http');