fix: removed thanks and username references in english guide (#34946)

guide/english/certifications/javascript-algorithms-and-data-structures/es6/compare-scopes-of-the-var-and-let-keywords/index.md

@@ -46,3 +46,7 @@ By using `let` you can declare variables in relation to their scope.
 - ["let" - *MDN Javascript reference*](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/let)
  - [Rauschmayer, Axel. "Variables and scoping in ECMAScript 6". *2ality.com*, 2015-02-07.](http://2ality.com/2015/02/es6-scoping.html) Accessed 11 Dec 2018. 
   - [Bos, Wes. "Quick Tip: Use let with for Loops in JavaScript". *wesbos.com*, 16 Aug 2016.](https://wesbos.com/for-of-es6/) Accessed 11 Dec 2018. 
+
+*   ![:warning:](https://forum.freecodecamp.com/images/emoji/emoji_one/warning.png?v=3 ":warning:") **DO NOT** add solutions that are similar to any existing solutions. If you think it is **_similar but better_**, then try to merge (or replace) the existing similar solution.
+*   Add an explanation of your solution.
+*   Categorize the solution in one of the following categories — **Basic**, **Intermediate** and **Advanced**. ![:traffic_light:](https://forum.freecodecamp.com/images/emoji/emoji_one/traffic_light.png?v=3 ":traffic_light:")

guide/english/certifications/javascript-algorithms-and-data-structures/es6/declare-a-read-only-variable-with-the-const-keyword/index.md

@@ -60,6 +60,3 @@ By using `const` on `sentence` we can make it read-only and by using `let` on `i
 *   ![:warning:](https://forum.freecodecamp.com/images/emoji/emoji_one/warning.png?v=3 ":warning:") **DO NOT** add solutions that are similar to any existing solutions. If you think it is **_similar but better_**, then try to merge (or replace) the existing similar solution.
 *   Add an explanation of your solution.
 *   Categorize the solution in one of the following categories — **Basic**, **Intermediate** and **Advanced**. ![:traffic_light:](https://forum.freecodecamp.com/images/emoji/emoji_one/traffic_light.png?v=3 ":traffic_light:")
-*   Please add your username only if you have added any **relevant main contents**. (![:warning:](https://forum.freecodecamp.com/images/emoji/emoji_one/warning.png?v=3 ":warning:") **_DO NOT_** _remove any existing usernames_)
-
-> See ![:point_right:](https://forum.freecodecamp.com/images/emoji/emoji_one/point_right.png?v=3 ":point_right:") <a href='http://forum.freecodecamp.com/t/algorithm-article-template/14272' target='_blank' rel='nofollow'>**`Wiki Challenge Solution Template`**</a> for reference.

guide/english/certifications/javascript-algorithms-and-data-structures/es6/mutate-an-array-declared-with-const/index.md

@@ -54,6 +54,3 @@ Trying to reassign a read-only `const` variable will throw an error, but by usin
 *   ![:warning:](https://forum.freecodecamp.com/images/emoji/emoji_one/warning.png?v=3 ":warning:") **DO NOT** add solutions that are similar to any existing solutions. If you think it is **_similar but better_**, then try to merge (or replace) the existing similar solution.
 *   Add an explanation of your solution.
 *   Categorize the solution in one of the following categories — **Basic**, **Intermediate** and **Advanced**. ![:traffic_light:](https://forum.freecodecamp.com/images/emoji/emoji_one/traffic_light.png?v=3 ":traffic_light:")
-*   Please add your username only if you have added any **relevant main contents**. (![:warning:](https://forum.freecodecamp.com/images/emoji/emoji_one/warning.png?v=3 ":warning:") **_DO NOT_** _remove any existing usernames_)
-
-> See ![:point_right:](https://forum.freecodecamp.com/images/emoji/emoji_one/point_right.png?v=3 ":point_right:") <a href='http://forum.freecodecamp.com/t/algorithm-article-template/14272' target='_blank' rel='nofollow'>**`Wiki Challenge Solution Template`**</a> for reference.

guide/english/certifications/javascript-algorithms-and-data-structures/es6/prevent-object-mutation/index.md

@@ -43,6 +43,11 @@ _You need to freeze the `MATH_CONSTANTS` object so that no one is able to alter
 
 By using Object.freeze() on `MATH_CONSTANTS` we can avoid manipulating it.
 
-
 ### Resources
 - ["Object.freeze()" - *MDN Javascript reference*](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/freeze)
+
+## ![:clipboard:](https://forum.freecodecamp.com/images/emoji/emoji_one/clipboard.png?v=3 ":clipboard:") NOTES FOR CONTRIBUTIONS:
+
+*   ![:warning:](https://forum.freecodecamp.com/images/emoji/emoji_one/warning.png?v=3 ":warning:") **DO NOT** add solutions that are similar to any existing solutions. If you think it is **_similar but better_**, then try to merge (or replace) the existing similar solution.
+*   Add an explanation of your solution.
+*   Categorize the solution in one of the following categories — **Basic**, **Intermediate** and **Advanced**. ![:traffic_light:](https://forum.freecodecamp.com/images/emoji/emoji_one/traffic_light.png?v=3 ":traffic_light:")

guide/english/certifications/javascript-algorithms-and-data-structures/es6/set-default-parameters-for-your-functions/index.md

@@ -64,7 +64,3 @@ Relevant Links:
 * :warning: DO NOT add solutions that are similar to any existing solutions. If you think it is similar but better, then try to merge (or replace) the existing similar solution.
 * Add an explanation of your solution.
 * Categorize the solution in one of the following categories — Basic, Intermediate and Advanced.  :traffic_light:
-* Please add your username only if you have added any relevant main contents. (  :warning: DO NOT remove any existing usernames)
-
-See  :point_right: [Wiki Challenge Solution Template](https://forum.freecodecamp.org/t/freecodecamp-algorithm-challenge-template-guide/14272) for reference.
-<!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->