Some improvement with README.md (#6557)

* Update README.md

* Add files via upload

* Delete discord.svg

* Delete slack_dark_mode.svg

* Delete slack_light_mode.svg

* Delete slack.png

Co-authored-by: supechicken666 <68530202+supechicken666@users.noreply.github.com>

README.md

@@ -4,6 +4,27 @@
 
 <p align="center">Package manager for Chrome OS</p>
 
+Chat with us!
+-------------
+<p><em>Discord is not currently syncing messages with Slack</em></p>
+
+<p>
+  <!-- dark/light mode detection, see https://docs.github.com/en/github/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#specifying-the-theme-an-image-is-shown-to -->
+  <a href="mailto:crewonslack@gmail.com?subject=Slack invitation link request&body=This email is auto-generated by README.md%0D%0A%0D%0A#gh-light-mode-only" target="_blank">
+    <img src="https://cdn.bfldr.com/5H442O3W/at/pl546j-7le8zk-838dm2/Slack_RGB.png?auto=webp&format=png#gh-light-mode-only" alt="Slack Invite" width="158px" height="40px" align="middle">
+  </a>
+  <a href="mailto:crewonslack@gmail.com?subject=Slack invitation link request&body=This email is auto-generated by README.md%0D%0A%0D%0A#gh-dark-mode-only" target="_blank">
+    <img src="https://cdn.bfldr.com/5H442O3W/at/pljt3c-dcwb20-27ztzl/Slack_RGB_White.png?auto=webp&format=png#gh-dark-mode-only" alt="Slack Invite" width="158px" height="40px" align="middle">
+  </a>
+  <img src="about:blank" width="15px"> <!-- acting a space between two images -->
+  <a href="https://discord.gg/QRrzBXN#gh-light-mode-only" target="_blank">
+    <img src="https://discord.com/assets/ff41b628a47ef3141164bfedb04fb220.png#gh-light-mode-only" alt="Discord Invite" width="201px" height="55px" align="middle">
+  </a>
+  <a href="https://discord.gg/QRrzBXN#gh-dark-mode-only" target="_blank">
+    <img src="https://discord.com/assets/2f71ab5383293f63985ac8d5c632b3d4.png#gh-dark-mode-only" alt="Discord Invite" width="201px" height="55px" align="middle">
+  </a>
+</p>
+
 Overview
 --------
 
@@ -15,12 +36,10 @@ Prerequisites
 You will need a Chromebook with developer mode enabled.  To do so, select your device on
 [the ChromiumOS Wiki](https://www.chromium.org/chromium-os/developer-information-for-chrome-os-devices) and follow the instructions listed there.
 
-Please be aware of the fact that developer mode is insecure if not properly configured. Setting a password as instructed in the VT-2 login screen is essential. It is also recommended to enable signed boot:
+Please be aware of the fact that developer mode is insecure if not properly configured. Setting a password as instructed in the VT-2 login screen is recommended. It is also recommended to enable signed boot:
 
-```bash
-sudo chromeos-setdevpasswd
-sudo crossystem dev_boot_signed_only=1
-```
+    sudo chromeos-setdevpasswd
+    sudo crossystem dev_boot_signed_only=1
 
 Supported Systems
 -----------------
@@ -32,7 +51,7 @@ Supported Systems
 | armv7l | Yes |
 | aarch64 | Yes |
 
-<sup>*</sup> <em>We can only provide limited support for i686 since Google has discontinued support.  Although we can no longer support gui apps, we will try to continue to support cli programs.</em>
+<sup>*</sup> <em>We can only provide limited support for i686 since Google has discontinued support.  Although we can no longer support GUI apps, we will try to continue to support CLI programs.</em>
 
 Installation
 ------------
@@ -128,15 +147,9 @@ Latest Packages
 | qtmultimedia | Qt Multimedia | 2021-08-30 |
 | qtscript | Qt Script Tools | 2021-08-30 |
 
-Chat with us!
--------------
-<p><em>Discord is not currently syncing messages with Slack</em></p>
-<p><a href="https://join.slack.com/t/chromebrew/shared_invite/enQtNDA2MTQ5ODQ3NDc2LTA0ZmJlMGFmNmZhOTYwNDE3ZDY0NDA0MWI0OTE3MzJkYTQxN2UxMWQ1YTEzOWFmNTliMGM4NDZjYzY2NjczZGE" target="_blank"><img src="/images/slack.png" alt="Slack Invite" />
-<a href="https://discord.gg/QRrzBXN" target="_blank"><img src="/images/discord.png" alt="Discord Invite" /></a></p>
-
 License
 -------
 
-Copyright 2013-2021 Michal Siwek and [all the awesome contributors](https://github.com/skycocker/chromebrew/graphs/contributors).
+Copyright 2013-2022 Michal Siwek and [all the awesome contributors](https://github.com/skycocker/chromebrew/graphs/contributors).
 
 This project including all of its source files is released under the terms of [GNU General Public License (version 3 or later)](http://www.gnu.org/licenses/gpl.txt).