Added references to the Linux and Windows build instructions

Added temporary instructions for how to install on Linux and Windows

README.md

@@ -25,10 +25,10 @@ You are in charge of your data and customizations.
     <a href="http://www.appflowy.io"><b>Website</b></a> •
     <a href="https://discord.gg/9Q2xaN37tV"><b>Discord</b></a> •
     <a href="https://twitter.com/appflowy"><b>Twitter</b></a> •
-    
-    
 
-    
+
+
+
 </p>  
 
 <p align="center"><img src="https://github.com/AppFlowy-IO/appflowy/blob/main/doc/imgs/welcome.png" alt="The Open Source Notion Alternative." width="1000px" /></p>
@@ -41,6 +41,47 @@ You are in charge of your data and customizations.
 brew install appflowy
 ```
 
+### Windows
+
+There is currently no Windows installer. However, you can download and install the app from the GitHub Releases section.
+1. Go to AppFlowy's [Releases](https://github.com/AppFlowy-IO/appflowy/releases/) page on GitHub.
+2. Download the current AppFlowy-Windows.zip file
+3. Create a directory in your %userprofile%\documents folder
+```shell
+md %userprofile%\documents\appflowy
+```
+4. Change to that directory
+```shell
+cd %userprofile%\documents\appflowy
+```
+5. Extract the downloaded zip file into the directory you just created.
+6. Run the application :
+```shell
+./app_flowy.exe
+```
+
+### Linux
+
+There is currently no Linux installer. However, you can download and install the app from the GitHub Releases section.
+1. Go to AppFlowy's [Releases](https://github.com/AppFlowy-IO/appflowy/releases/) page on GitHub.
+2. Download the current AppFlowy-Linux.tar.gz file.
+3. Create a directory in your /opt/ folder.
+```shell
+md /opt/appflowy
+```
+4. Change to that directory
+```shell
+cd /opt/appflowy
+```
+5. Extract the downloaded compressed file into the directory you just created.
+```shell
+tar -xvf AppFlowy-Linux.tar.gz
+```
+6. Run the application :
+```shell
+./app_flowy
+```
+
 ## Built With
 
 * [Flutter](https://flutter.dev/)
@@ -53,6 +94,14 @@ brew install appflowy
 
 ## Getting Started
 
+### Linux
+Please follow these instructions to build on [Linux](doc/BUILD_ON_LINUX.md).
+
+### Windows
+Please follow these instructions to build on [Windows](doc/BUILD_ON_WINDOWS.md).
+
+### macOS
+
 How to build on MacOS, please follow these simple steps.
 
 **Step 1:**
@@ -81,7 +130,7 @@ cargo make install_targets
 
 >
 >
-> 🚀 Skip install_rust or install_cargo_make if you already installed it. 
+> 🚀 Skip install_rust or install_cargo_make if you already installed it.
 > FYI, AppFlowy uses [https://github.com/sagiegurari/cargo-make](https://github.com/sagiegurari/cargo-make) to construct the build scripts
 
 **Step 3:**
@@ -107,8 +156,8 @@ flutter config --enable-linux-desktop
 ```
 
 * Open the `app_flowy` folder located at xx/appflowy/frontend with Visual Studio Code or other IDEs at your disposal.
-* Go to the Run and Debug tab and then click the run button. 
-![Run the project](https://github.com/AppFlowy-IO/appflowy/blob/main/doc/imgs/run.png) 
+* Go to the Run and Debug tab and then click the run button.
+![Run the project](https://github.com/AppFlowy-IO/appflowy/blob/main/doc/imgs/run.png)
 
 * If you want to build for the other platform, you should modify the build_sdk.sh before running.
 ![build_sdk](https://user-images.githubusercontent.com/86001920/143262377-bb49e913-10ca-4198-80ec-bd814a13ee1d.png)
@@ -117,7 +166,7 @@ Please also check the device selection, AppFlowy only supports Desktop by now:
 
 
 * If you encounter any issues, have a look at [Troubleshooting](https://github.com/AppFlowy-IO/appflowy/wiki/Troubleshooting) first. If your issue is not included in the page, please create an [issue](https://github.com/AppFlowy-IO/appflowy/issues/new/choose) or ask on [Discord](https://discord.gg/9Q2xaN37tV).
-  
+
 ## Roadmap
 
 [AppFlowy Roadmap](https://trello.com/b/NCyXCXXh/appflowy-roadmap)