020 linux fundamentals url fix (#857)

* Update Challenge-03.md

Fixed an incorrect URL in the success criteria

* Update Challenge-03.md

* Update Challenge-03.md

* Update Challenge-03.md

020-LinuxFundamentals/Student/Challenge-03.md

@@ -8,7 +8,7 @@ In this challenge you will learn basic commands about file manipulation such as
 
 - Find in the `/var` directory all the files that have been modified in the last 60 minutes
 - Show the type of file of `/bin/htop`, `/etc/passwd` and `/usr/bin/passwd`
-- Go to your home directory and download [azure-linux.svg](https://docs.microsoft.com/en-us/learn/achievements/azure-linux.svg)  and [InfographicRC2.pdf](https://azure.microsoft.com/mediahandler/files/resourcefiles/infographic-reliability-with-microsoft-azure/InfographicRC2.pdf) 
+- Go to your home directory and download [`azure-linux.svg`](https://docs.microsoft.com/en-us/learn/achievements/azure-linux.svg)  and [`InfographicRC2.pdf`](https://azure.microsoft.com/mediahandler/files/resourcefiles/infographic-reliability-with-microsoft-azure/InfographicRC2.pdf) 
 - Display the type of file of `azure-linux.svg` and `InfographicRC2.pdf`
 - Rename `azure-linux.svg` to `azure-linux.pdf` 
 - Display the type of file of `azure-linux.pdf` and `InfographicRC2.pdf`
@@ -27,7 +27,7 @@ In this challenge you will learn basic commands about file manipulation such as
 
 1. Show all the files that have been modified in the last 60 minutes within `/var`
 2. Make sure you checked the different file types of the files `/bin/htop`, `/etc/passwd` and `/usr/bin/passwd`
-3. Ensure you were able to download the files [azure-linux.svg](https://docs.microsoft.com/en-us/learn/achievements/azure-linux.svg)  and [azure-ops-guide.pdf](https://docsmsftpdfs.blob.core.windows.net/guides/azure/azure-ops-guide.pdf) successfully into your home diretory
+3. Ensure you were able to download the files [`azure-linux.svg`](https://docs.microsoft.com/en-us/learn/achievements/azure-linux.svg) and [`InfographicRC2.pdf`](https://azure.microsoft.com/mediahandler/files/resourcefiles/infographic-reliability-with-microsoft-azure/InfographicRC2.pdf) successfully into your home directory
 4. Confirm the different file types 
 5. Validate the renaming of `azure-linux.svg` to `azure-linux.pdf` 
 6. After the renaming of the extension, check if the file type was changed
@@ -36,7 +36,7 @@ In this challenge you will learn basic commands about file manipulation such as
 9. Confirm the creation date and time for each file
 10. Make sure you have changed the date properly to yesterday's date
 11. Confirm if the creation date and time were defined as expected
-12. Validate if the all files from `~/lab` were sucessfully placed into `~/mybackup`
+12. Validate if the all files from `~/lab` were successfully placed into `~/mybackup`
 13. Make sure if you were able to remove everything using just one command 
 14. Show all log files copied from `/var/log` into `~/logbackup`
 15. Confirm how many lines exist in `/etc/wgetrc`