title: ejs form redirects to double copy of URL(express.js)
body: <p>I am new to backend and I am having trouble getting the express post method to work. 
  I created a file called new.ejs which contains a form that redirects to a URL <a href="http://localhost:3000/campgrounds/" rel="nofollow noreferrer">http://localhost:3000/campgrounds/</a></p>
  
  <p><strong>new.ejs file</strong></p>
  
  <pre><code>&lt;% include partials/header %&gt;
  
      &lt;h1&gt;Create a new campground&lt;/h1&gt;
  
      &lt;form action="campgrounds" method="POST"&gt;
          &lt;input type="text" name='name' placeholder="name" &gt;
          &lt;input type="text" name='image' placeholder="img-url"&gt;
          &lt;button&gt;Submit!&lt;/button&gt;
      &lt;/form&gt;
  
  &lt;% include partials/footer %&gt;
  </code></pre>
  
  <p>I reviewed my index.js file and I don't see any problems whatsoever. but when I click the submit button, it redirects me to <code>http://localhost:3000/campgrounds/campgrounds</code> instead if <code>http://localhost:3000/campgrounds/</code></p>
  
  <p><strong>index.js file</strong></p>
  
  <pre><code>const express = require('express');
  const app = express();
  const bodyParser = require("body-parser");
  
  app.use(bodyParser.urlencoded({extended: true}));
  app.set('view engine', 'ejs');
  
  let campgrounds = [
      {name: "salmon creek", image: "https://pixabay.com/get/e837b1072af4003ed1584d05fb1d4e97e07ee3d21cac104491f4c278a7eeb1bc_340.jpg"},
      {name: "Granite Hill", image: "https://pixabay.com/get/e83db7082af3043ed1584d05fb1d4e97e07ee3d21cac104491f4c278a7eeb1bc_340.jpg"},
      {name: "Mountain Goat's Rest", image: "https://pixabay.com/get/ef3cb00b2af01c22d2524518b7444795ea76e5d004b0144591f3c079a4e9b1_340.jpg"}
  ]
  
  
  app.get('/', (req, res) =&gt; {
      res.render('landing');
  });
  
  app.get('/campgrounds', (req, res) =&gt; {
  
      res.render("campgrounds", {campgrounds: campgrounds});
  });
  
  app.post('/campgrounds', (req, res) =&gt; {
    let name = req.body.name;
    let image = req.body.image;
    let newCampground= {name: name, image: image}
    campgrounds.push(newCampground);
  
    res.redirect('/campgrounds')
  });
  
  app.get('/campgrounds/new', (req, res) =&gt; {
      res.render('new')
  });
  
  app.listen(3000, () =&gt; {
      console.log('Now serving app listening on port 3000!');
  });
  </code></pre>
  
  <p>I cannot get this app.post to work. but all other app.get method is working fine. </p>