Update README.md

[tmiland]

Add manual commands to Debian and Ubuntu install instructions.

Got a pubkey error on Ubuntu. Added instructions from: https://crystal-lang.org/reference/installation/on_debian_and_ubuntu.html

[dimqua]

Shouldn't this information be moved to the wiki?

[Perflyst]

The wiki is probably a better place for this. setup.sh executes apt-key adv --keyserver keys.gnupg.net --recv-keys 09617FD37CC06B54 which should work on any ubuntu and debian.

[tmiland]

Shouldn't this information be moved to the wiki?

Probably.

The wiki is probably a better place for this. setup.sh executes apt-key adv --keyserver keys.gnupg.net --recv-keys 09617FD37CC06B54 which should work on any ubuntu and debian.

Wasn't setup.sh removed? It's not in my repos. 🙂

[Perflyst]

I am talking about this setup.sh: curl -sSL https://dist.crystal-lang.org/apt/setup.sh | sudo bash

[tmiland]

I am talking about this setup.sh: curl -sSL https://dist.crystal-lang.org/apt/setup.sh | sudo bash

Ah, okay. Well, then, that's the main reason i added the above to the readme, in case someone else would get the same error.

Err:18 https://dist.crystal-lang.org/apt crystal InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 09617FD37CC06B54
Reading package lists... Done 
W: GPG error: https://dist.crystal-lang.org/apt crystal InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 09617FD37CC06B54
E: The repository 'https://dist.crystal-lang.org/apt crystal InRelease' is not signed.
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.

This is from --> setup.sh: curl -sSL https://dist.crystal-lang.org/apt/setup.sh | sudo bash

[omarroth]

LGTM 👍