CI revamp part 2 (#1875)

* Added Makefile
* Updated README with the new information
* Updated Github Actions
* Added FreeBSD ARM builds
* Prepared to our internal CI
* Improved the auto-update version check

README.md

@@ -14,9 +14,6 @@
     <a href="https://twitter.com/AdGuard">Twitter</a> |
     <a href="https://t.me/adguard_en">Telegram</a>
     <br /><br />
-    <a href="https://travis-ci.com/AdguardTeam/AdGuardHome">
-      <img src="https://travis-ci.com/AdguardTeam/AdGuardHome.svg" alt="Build status" />
-    </a>
     <a href="https://codecov.io/github/AdguardTeam/AdGuardHome?branch=master">
       <img src="https://img.shields.io/codecov/c/github/AdguardTeam/AdGuardHome/master.svg" alt="Code Coverage" />
     </a>
@@ -153,17 +150,11 @@ Is there a chance to handle this in the future? DNS will never be enough to do t
 
 ### Prerequisites
 
-You will need:
+You will need this to build AdGuard Home:
 
  * [go](https://golang.org/dl/) v1.14 or later.
  * [node.js](https://nodejs.org/en/download/) v10 or later.
 
-You can either install them via the provided links or use [brew.sh](https://brew.sh/) if you're on Mac:
-
-```bash
-brew install go node
-```
-
 ### Building
 
 Open Terminal and execute these commands:
@@ -174,15 +165,26 @@ cd AdGuardHome
 make
 ```
 
-#### (For devs) Upload translations
-```
-node upload.js
-```
+Check the [`Makefile`](https://github.com/AdguardTeam/AdGuardHome/blob/master/Makefile) to learn about other commands.
 
-#### (For devs) Download translations
-```
-node download.js
-```
+#### Preparing release
+
+You'll need this to prepare a release build:
+
+* [goreleaser](https://goreleaser.com/)
+* [snapcraft](https://snapcraft.io/)
+
+Run `make snapshot` or `make release` to build all AdGuard distrs.
+
+#### Docker image
+
+* Run `make docker` to build the Docker image locally.
+* Run `make docker-multi-arch` to build the multi-arch Docker image (the one that we publish to Docker Hub).
+
+### Resources that we update periodically
+
+* `scripts/translations`
+* `scripts/whotracksme`
 
 <a id="contributing"></a>
 ## Contributing