Add config path next to executable

Searching for config only in cwd isn't intuitive for end users.

README.md

@@ -7,7 +7,7 @@ OPDS 1.1 and web server for `.inpx` libraries with full-text search.
 ### Standalone
 
 Download the latest release.
-Download [`inpxer-example.toml`](./inpxer-example.toml), rename to `inpxer.toml`, put near executable and edit to your liking.
+Download [`inpxer-example.toml`](./inpxer-example.toml), rename to `inpxer.toml`, put next to executable (or current working directory) and edit to your liking.
 
 Import data:
 ```shell

internal/config/config.go

@@ -2,10 +2,14 @@ package config
 
 import (
 	"os"
+	"path"
+	"path/filepath"
 
 	"github.com/pelletier/go-toml/v2"
 )
 
+const configFilename = "inpxer.toml"
+
 type MyConfig struct {
 	Language    string       `toml:"language"`
 	Title       string       `toml:"title"`
@@ -25,8 +29,15 @@ type Converter struct {
 
 func Load() (*MyConfig, error) {
 	configFiles := []string{
-		"inpxer.toml",
-		"/data/inpxer.toml",
+		configFilename,
+		path.Join("/data", configFilename),
+	}
+
+	exe, err := os.Executable()
+	if err == nil {
+		exePath := filepath.Dir(exe)
+		exeConf := filepath.Join(exePath, configFilename)
+		configFiles = append(configFiles, exeConf)
 	}
 
 	var configFile string