replace deprecated collection methods/usage

Author: almostSouji

guide/popular-topics/common-questions.md

@@ -33,7 +33,7 @@ member.kick();
 <!-- eslint-skip -->
 
 ```js
-const role = <guild>.roles.find('name', '<role name>');
+const role = <guild>.roles.find(role => role.name === '<role name>');
 const member = <message>.mentions.members.first();
 member.addRole(role);
 ```
@@ -44,7 +44,7 @@ member.addRole(role);
 
 ```js
 const member = <message>.mentions.members.first();
-if (member.roles.exists('name', '<role name>')) {
+if (member.roles.some(role => role.name === '<role name>')) {
 // ...
 }
 ```

guide/popular-topics/reactions.md

@@ -68,7 +68,7 @@ Using `.find()`, your code would look something like this:
 
 ```js
 if (message.content === '!react-custom') {
-const emoji = message.guild.emojis.find('name', 'ayy');
+const emoji = message.guild.emojis.find(emoji => emoji.name === 'ayy');
 message.react(emoji);
 }
 ```