docs: deploy docs using netlify (#4774)

This adds in the legacy docs into the repo and enables automatic deployment via netlify. The netlify-docs.js script will error out the build on netlify on master if we're not on a tagged commit so that it won't redeploy the docs unless there's a new release. If we're not on master or on master with a tagged commit, it will process with the deploy.
Also, this removes the API docs from being published with npm, fixes #4609.

docs/legacy-docs/js/guides.js

@@ -0,0 +1,122 @@
+var BCLS = ( function () {
+    var heading = document.getElementsByTagName('h1')[0],
+        title = document.getElementsByTagName('title')[0],
+        sections = document.getElementsByTagName('h2'),
+        links = document.getElementsByTagName('a'),
+        sidenav = document.getElementById('sidenav'),
+        navList,
+        navA,
+        navItem,
+        navText,
+        i,
+        iMax,
+        item;
+
+    /**
+     * tests for all the ways a variable might be undefined or not have a value
+     * @param {*} x the variable to test
+     * @return {Boolean} true if variable is defined and has a value
+     */
+    function isDefined (x){
+        if ( x === "" || x === null || x === undefined || x === NaN) {
+            return false;
+        }
+        return true;
+    }
+
+    function buildSideNav() {
+        if (isDefined(sections)) {
+            var homeHead = document.createElement('p'),
+                homeLink = document.createElement('a');
+            homeLink.setAttribute('href', '../../index.html');
+            homeLink.setAttribute('style', 'font-size:1.4em;font-weight:bold;text-align:right;margin:0;padding-left:1em');
+            homeLink.textContent = 'Docs Index';
+            homeHead.appendChild(homeLink);
+            navList = document.createElement('ul');
+            navList.setAttribute('class', 'sidenav-list');
+            navItem = document.createElement('li');
+            navA = document.createElement('a');
+            navA.setAttribute('href', '#toc0');
+            navText = document.createTextNode('Top');
+            navA.appendChild(navText);
+            navItem.appendChild(navA);
+            navList.appendChild(navItem);
+            iMax = sections.length;
+            for (i = 0; i < iMax; i++) {
+                item = sections[i];
+                navItem = document.createElement('li');
+                navA = document.createElement('a');
+                navA.setAttribute('href', '#' + item.id );
+                navText = document.createTextNode(item.textContent);
+                navA.appendChild(navText);
+                navItem.appendChild(navA);
+                navList.appendChild(navItem);
+            }
+            sidenav.appendChild(homeHead);
+            sidenav.appendChild(navList);
+        }
+    }
+
+    /**
+     * fix link paths to point to html instead of md
+     */
+    function fixLinks() {
+        var i,
+            iMax = links.length,
+            link,
+            url;
+        for (i = 0; i < iMax; i += 1) {
+            link = links[i];
+            url = link.getAttribute('href');
+            if (isDefined(url)) {
+                // if CONTRIBUTING.md, don't change
+                if (url.indexOf('CONTRIBUTING.md' === -1)) {
+                    url.replace('.md', '.html');
+                    link.setAttribute('href', url);
+                }
+            }
+        }
+    }
+
+    /**
+     * set the doc title
+     */
+    function setTitle() {
+        title.textContent = 'Videojs ' + heading.textContent;
+    }
+
+    /**
+     * add the page footer
+     */
+    function addFooter() {
+        var path = document.location.pathname,
+            footer = document.createElement('div'),
+            srcLink = document.createElement('a'),
+            srcLink2 = document.createElement('a'),
+            main = document.getElementById('main'),
+            srcPath,
+            srcPath2;
+        // extract file name
+        if (path.indexOf('#') > 0) {
+            path = path.substring(0, path.indexOf('#'));
+        }
+        path = path.substring(path.lastIndexOf('/') + 1);
+        srcPath = 'https://github.com/videojs/video.js/blob/master/docs/guides/' + path;
+        srcPath2 = 'https://github.com/videojs/docs';
+        footer.setAttribute('class', 'footer');
+        srcLink.setAttribute('href', srcPath);
+        srcLink.appendChild(document.createTextNode('content source'));
+        srcLink2.setAttribute('href', srcPath2);
+        srcLink2.appendChild(document.createTextNode('doc generator'));
+        footer.innerHTML = 'Want to contribute? Go to the ';
+        footer.appendChild(srcLink);
+        footer.innerHTML += ' or the ';
+        footer.appendChild(srcLink2);
+        main.appendChild(footer);
+    }
+
+    setTitle();
+    buildSideNav();
+    fixLinks();
+    addFooter();
+})();