Following instructions for installing on Debian fails when using Docker

[mkindahl]

Use this template for reporting bugs in the docs.

Describe the bug

Following the instructions on https://docs.timescale.com/self-hosted/latest/install/installation-linux/ for installing on Debian Linux into a docker container fails.

What do the docs say now?

5. Update your local repository list:

apt update

What should the docs say?

It currently gives an error when I run it in Docker (using ubuntu:18.04 and ubuntu:20.04).

root@714750e5130e:/# apt-get update
Hit:1 http://apt.postgresql.org/pub/repos/apt focal-pgdg InRelease
Hit:2 http://security.ubuntu.com/ubuntu focal-security InRelease                                                          
Hit:3 http://archive.ubuntu.com/ubuntu focal InRelease                                                                    
Hit:4 http://archive.ubuntu.com/ubuntu focal-updates InRelease        
Hit:5 http://archive.ubuntu.com/ubuntu focal-backports InRelease      
Ign:6 https://packagecloud.io/timescale/timescaledb/debian focal InRelease
Err:7 https://packagecloud.io/timescale/timescaledb/debian focal Release
  404  Not Found [IP: 54.67.94.32 443]
Reading package lists... Done                  
E: The repository 'https://packagecloud.io/timescale/timescaledb/debian focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Page affected

https://docs.timescale.com/self-hosted/latest/install/installation-linux/

Subject matter expert (SME)

Any further info

Contributing to documentation

We welcome documentation contributions!

• For information about how to propose a change, see the contributing guide in our GitHub repository.
• For information on style and word usage, see the style guide

[mkindahl]

Was not using the Ubuntu source repository, but rather the Debian. Sorry about that.