Added a new sync that uses hash

Added a new sync that uses hash and sqlc for the queries. Added db
migration. Started adding a config file.

pkg/server/config.go

@@ -0,0 +1,34 @@
+package server
+
+import (
+	"fmt"
+	"os"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Config struct {
+	Host     string
+	Port     int
+	User     string
+	Password string
+	Dbname   string
+	Path     string
+}
+
+var Conf *Config
+
+func ReadConf(filename string) error {
+	buf, err := os.ReadFile(filename)
+	if err != nil {
+		return err
+	}
+
+	c := &Config{}
+	err = yaml.Unmarshal(buf, c)
+	if err != nil {
+		return fmt.Errorf("in file %q: %w", filename, err)
+	}
+	Conf = c
+	return err
+}