How to get a runtime_info as a file

instructions.md

❯ iex
Erlang/OTP 22 [erts-10.6.2] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe]

Interactive Elixir (1.10.0-rc.0) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> file = File.open!("./runtime_info.txt", [:write])
#PID<0.110.0>
iex(2)> original_group_leader = Process.group_leader()
#PID<0.64.0>
iex(3)> Process.group_leader(self(), file)
iex(4)> runtime_info()
iex(5)> Process.group_leader(self(), original_group_leader)
true
iex(6)> IO.puts("back to original group leader")
back to original group leader
:ok
iex(7)>
BREAK: (a)bort (c)ontinue (p)roc info (i)nfo (l)oaded
       (v)ersion (k)ill (D)b-tables (d)istribution
^C
❯ cat runtime_info.txt
true

## System and architecture

Elixir version:     1.10.0-rc.0
Erlang/OTP version: 22
ERTS version:       10.6.2
Compiled for:       x86_64-apple-darwin18.7.0
Schedulers:         8
Schedulers online:  8

## Memory

Total:              42 MB
Atoms:              331 KB
Binaries:           549 KB
Code:               5 MB
ETS:                557 KB
Processes:          24 MB

## Statistics / limits

Uptime:             33 seconds
Run queue:          1
Atoms:              12207 / 1048576 (1% used)
ETS:                23 / 8192 (0% used)
Ports:              3 / 65536 (0% used)
Processes:          58 / 262144 (0% used)

Showing topics:     [:system, :memory, :limits]
Additional topics:  [:allocators, :applications]

To view a specific topic call runtime_info(topic)