remove MDN links from English challenges (#39337)

* remove MDN links from English challenges

* add push challenge reference to record-collection

* refactor truthy falsy verbiage

* replace MDN link with news link

* remove unnecessary whitespace

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/increment-a-number-with-javascript.english.md

@@ -19,7 +19,6 @@ is the equivalent of
 ## Instructions
 <section id='instructions'>
 Change the code to use the <code>++</code> operator on <code>myVar</code>.
-<strong>Hint</strong><br>Learn more about <a href="https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Increment_()" target="_blank">Arithmetic operators - Increment (++)</a>.
 </section>
 
 ## Tests

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/record-collection.english.md

@@ -18,7 +18,7 @@ If <code>prop</code> is <code>"tracks"</code> but the album doesn't have a <code
 If <code>prop</code> is <code>"tracks"</code> and <code>value</code> isn't empty (<code>""</code>), push the <code>value</code> onto the end of the album's existing <code>tracks</code> array.
 If <code>value</code> is empty (<code>""</code>), delete the given <code>prop</code> property from the album.
 <strong>Hints</strong><br>Use <code>bracket notation</code> when <a href="/learn/javascript-algorithms-and-data-structures/basic-javascript/accessing-object-properties-with-variables" target="_blank">accessing object properties with variables</a>.
-Push is an array method you can read about on <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/push" target="_blank">Mozilla Developer Network</a>.
+The `push` array method will be helpful here. Check out our <a href="https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/basic-javascript/manipulate-arrays-with-push" target="_blank">Manipulate Arrays With push()</a> challenge to review how it works.
 You may refer back to <a href="/learn/javascript-algorithms-and-data-structures/basic-javascript/manipulating-complex-objects" target="_blank">Manipulating Complex Objects</a> Introducing JavaScript Object Notation (JSON) for a refresher.
 </section>
 

curriculum/challenges/english/03-front-end-libraries/jquery/change-text-inside-an-element-using-jquery.english.md

@@ -14,7 +14,7 @@ Here's how you would rewrite and emphasize the text of our heading:
 <code>$("h3").html("&#60;em&#62;jQuery Playground&#60;/em&#62;");</code>
 jQuery also has a similar function called <code>.text()</code> that only alters text without adding tags. In other words, this function will not evaluate any HTML tags passed to it, but will instead treat it as the text you want to replace the existing content with.
 Change the button with id <code>target4</code> by emphasizing its text.
-<a href="https://developer.mozilla.org/en/docs/Web/HTML/Element/em" target="_blank">View the MDN web docs for &#60;em&#62;</a> to learn the difference between <code>&#60;i&#62;</code> and <code>&#60;em&#62</code> and their uses.
+<a href="https://www.freecodecamp.org/news/html-elements-explained-what-are-html-tags/#em-element" target="_blank">View our news article for &#60;em&#62;</a> to learn the difference between <code>&#60;i&#62;</code> and <code>&#60;em&#62</code> and their uses.
 Note that while the <code>&#60;i&#62;</code> tag has traditionally been used to emphasize text, it has since been adopted for use as a tag for icons. The <code>&#60;em&#62;</code> tag is now widely accepted as the tag for emphasis. Either will work for this challenge.
 </section>
 

curriculum/challenges/english/06-quality-assurance/quality-assurance-and-testing-with-chai/use-assert.isok-and-assert.isnotok.english.md

@@ -12,8 +12,7 @@ forumTopicId: 301607
 As a reminder, this project is being built upon the following starter project on <a href='https://glitch.com/edit/#!/remix/clone-from-repo?REPO_URL=https://github.com/freeCodeCamp/boilerplate-mochachai/'>Glitch</a>, or cloned from <a href='https://github.com/freeCodeCamp/boilerplate-mochachai/'>GitHub</a>.
 
 <code>isOk()</code> will test for a truthy value and <code>isNotOk()</code> will test for a falsy value.
-[Truthy reference](https://developer.mozilla.org/en-US/docs/Glossary/Truthy)
-[Falsy reference](https://developer.mozilla.org/en-US/docs/Glossary/Falsy)
+To learn more about truthy and falsy values, try our <a href="https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/basic-algorithm-scripting/falsy-bouncer" target="_blank">Falsy Bouncer</a> challenge.
 </section>
 
 ## Instructions