chore: unify terms used

Author: nazarewk

src/pages/how-to/troubleshooting-client.mdx

@@ -534,7 +534,7 @@ Nameservers:
 ...
 ```
 
-#### Confirming the DNS names resolve properly in practice
+#### Verifying the DNS names resolve properly in practice
 
 Here is a short summary of commands querying nameservers for `name.at.example.com` in different operating systems.
 The `.` at the end makes sure you are querying a fully-qualified names independent of your local network's configuration
@@ -553,7 +553,7 @@ resolvectl query name.at.example.com.
 
 ```
 
-#### Confirming the nameservers are properly registered in Windows operating system
+#### Verifying the nameservers are properly registered in Windows operating system
 
 To confirm the nameservers are properly registered in Windows operating system using PowerShell:
 
@@ -585,7 +585,7 @@ You should be searching for following in the outputs of above commands:
 - `.netbird.cloud` and `.XXX.100.in-addr.arpa` under matching _Namespace_ for built-in entries,
 - `.your.custom.domain.example.com` under matching _Namespace_ for your custom domains,
 
-#### Confirming the nameservers are properly registered in MacOS operating system
+#### Verifying the nameservers are properly registered in MacOS operating system
 
 To confirm the nameservers are properly registered in MacOS operating system using terminal:
 
@@ -617,7 +617,7 @@ You should be searching for following in the outputs of above commands:
 - `.your.custom.domain.example.com` under matching _domain_ for your custom domains,
 - `Reachable` under `reach` field,
 
-#### Confirming the nameservers are properly registered in Linux operating system
+#### Verifying the nameservers are properly registered in Linux operating system
 
 Nameserver can be configured in different ways depending on your specific distribution's configuration: