feat: support CONFIG env variable for file

Containerfile

@@ -25,7 +25,7 @@ RUN pacman -Syu --noconfirm \
     python-xattr \
     python-pyxattr
 
-COPY <<-EOT /app/config.toml
+COPY <<-EOT /data/config.toml
     dry_run = false
     out_dir = "/data/vids"
 

README.md

@@ -48,6 +48,17 @@ E.g. from Chromium:
 yt-dlp --cookies-from-browser chromium --cookies cookies.txt
 ```
 
+## Container
+
+```
+podman run --rm \
+    --env='CONFIG=/data/config.toml' \
+    --volume=path/to/config:/data/config.toml \
+    --volume=path/to/opml:/data/opml.xml \
+    --volume=path/to/cookies:/data/cookies.txt
+    registry.meatbag.se/varl/subsyt
+```
+
 ## Result
 
 ```

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"log"
+	"os"
 
 	"git.meatbag.se/varl/subsyt/internal/config"
 	"git.meatbag.se/varl/subsyt/internal/dl"
@@ -9,7 +10,13 @@ import (
 )
 
 func main() {
-	cfg, err := config.Load("./config.toml")
+	configPath := os.Getenv("CONFIG")
+
+	if configPath == "" {
+		configPath = "./config.toml"
+	}
+
+	cfg, err := config.Load(configPath)
 	if err != nil {
 		panic(err)
 	}