Update README

README.md

@@ -1,32 +1,66 @@
 # wallhaven-sync
 wallhaven-sync is a command-line tool for syncing your favorite wallpapers from Wallhaven's Favorites page to a local directory on your computer. wallhaven-sync can also detect wallpapers in your local sync directory that are not favorite on Wallhaven anymore and delete them.
 
+## Installation
+### Using prebuilt binaries
+Prebuilt binaries are provided on [Github Releases](https://github.com/amogh09/wallhaven-sync/releases) for Linux and MacOS platforms. Download the relevant binary for your platform from the Releases page and they should be ready for use.
+
+### Installing from source
+Follow the steps below to build `wallhaven-sync` from source. You will need a working [cabal](https://www.haskell.org/cabal/download.html) tool with GHC 9.2.4 for the build.
+
+1. Download the source from one of the [releases](https://github.com/amogh09/wallhaven-sync/releases).
+1. Inside the source directory, invoke `cabal install`.
+1. `wallhaven-sync` will be installed in your `.cabal/bin` directory.
+
 ## Usage
-`wallhaven-sync` requires your Wallhaven authentication token in order to fetch your favorite wallpapers from Wallhaven. The tool will look for the authentication token in `WALLHAVEN_COOKIE` environment variable. You need to set this environment variable with your authentication token value. 
+`wallhaven-sync` requires your Wallhaven API Key. 
+
+1. Log into your [Wallhaven](https://wallhaven.cc/) account and then open the [Account Settings](https://wallhaven.cc/settings/account) page. 
+1. Your API key will be shown under "API Key" section as shown in the image below.
+![Wallhaven API Key](/assets/images/api_key.png "Wallhaven API Key")
 
 Usage instructions can be printed by invoking `wallhaven-sync --help`. The help output is reproduced below.
 
 ```
 wallhaven-sync
 
-Usage: wallhaven-sync [--wallpaper-dir DIRECTORY] [--num-parallel-downloads NUM]
-                      [--num-retries NUM] [--retry-delay NUM] [--delete-unliked]
+Usage: wallhaven-sync [--wallpaper-dir DIRECTORY] [--delete-unliked]
+                      --wallhaven-username USERNAME --wallhaven-api-key API_KEY
+                      [--collection-label LABEL] [--debug]
 
-  Sync wallpapers from Wallhaven favorites
+  Sync wallpapers from a Wallhaven collection
 
 Available options:
   --wallpaper-dir DIRECTORY
                            Directory where wallpapers will be saved
                            (default: "/Users/home/wallpapers")
-  --num-parallel-downloads NUM
-                           Number of wallpapers to download in parallel
-                           (default: 5)
-  --num-retries NUM        Number of retries to perform when downloading a
-                           wallpaper (default: 5)
-  --retry-delay NUM        Number of seconds to wait between retries
-                           (default: 3)
   --delete-unliked         Delete unliked wallpapers
+  --wallhaven-username USERNAME
+                           Wallhaven username
+  --wallhaven-api-key API_KEY
+                           Wallhaven API key
+  --collection-label LABEL Label of the collection to sync (default: "Default")
+  --debug                  Debug mode
   -h,--help                Show this help text
-  ```
+```
+
+### Options
+| Option | Description | Default value | Required |
+| ------ | ----------- | ------------- | -------- |
+| `--wallpaper-dir` | Local directory to use for downloading the wallpapers. | `/Users/home/wallpapers` | No |
+| `--wallhaven-username` | Username of the collection owner. | | Yes |
+| `--collection-label` | Name of the collection to download. | Default | No |
+| `wallhaven-api-key` | Your wallhaven API key. | | Yes |
+| `--delete-unliked` | If this flag is present then `wallhaven-sync` will delete wallpapers that are in the local directory but not in the specified collection. This option is useful for deleting wallpapers that were unliked from your collection. | NA | No |
+
+### For downloading your Wallhaven favorites to default directory
+`wallhaven-sync --wallhaven-username USERNAME --wallhaven-api-key API_KEY`
+
+### For downloading your wallhaven favorites to ~/wallhaven directory
+`wallhaven-sync --wallhaven-username USERNAME --wallhaven-api-key API_KEY --wallpaper-dir ~/wallhaven`
+
+### For syncing (deleting unliked wallpapers from local directory and downloading wallpapers from the collection) Wallhaven favorites to default directory
+`wallhaven-sync --wallhaven-username USERNAME --wallhaven-api-key API_KEY --delete-unliked`
 
-All options have sensible defaults and invoking `wallhaven-sync` command will download all your favorite wallpapers from Wallhaven to `/Users/home/wallpapers` directory. The directory will be created if it does not exist.
+### For downloading a collection named "nature" under account "my-account" to default directory
+`wallhaven-sync --wallhaven-username my-account --collection-label nature --wallhaven-api-key API_KEY`