[BUG] linux installation instruction doesn't work on arm64 linux

[weideng1]

Describe the bug

Following the instructions here can get astra-cli installed, but it's not the right binary.

To Reproduce

Steps to reproduce the behavior:

1. On a arm64 Mac, install Ubuntu VM:

multipass launch --name quick-ubuntu
multipass shell quick-ubuntu
apt-get install unzip

2. Run the following command to install astra-cli:

curl -Ls "https://dtsx.io/get-astra-cli" | bash

3. exit the shell and re-enter and run astra command, you will get the following error:

ubuntu@quick-ubuntu:~$ astra
-bash: /home/ubuntu/.astra/cli/astra: cannot execute binary file: Exec format error

ubuntu@quick-ubuntu:~$ file `which astra`
/home/ubuntu/.astra/cli/astra: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=3ccff395f3802f6cde2c92cb155ad1f109b5541c, for GNU/Linux 3.2.0, with debug_info, not stripped

Expected behavior
astra installation for linux should get the correct binary installed, regardless of arch.

Desktop (please complete the following information):

• OS: MacOS arm64 using multipass VM from Canonical
• Version 0.5