Add config file and rework cli parsing and passing of config values (#263)

Co-authored-by: 6543 <6543@obermui.de>
Reviewed-on: https://codeberg.org/Codeberg/pages-server/pulls/263
Reviewed-by: 6543 <6543@obermui.de>
Co-authored-by: crapStone <me@crapstone.dev>
Co-committed-by: crapStone <me@crapstone.dev>

config/config.go

@@ -0,0 +1,46 @@
+package config
+
+type Config struct {
+	LogLevel string `default:"warn"`
+	Server   ServerConfig
+	Gitea    GiteaConfig
+	Database DatabaseConfig
+	ACME     ACMEConfig
+}
+
+type ServerConfig struct {
+	Host               string `default:"[::]"`
+	Port               uint16 `default:"443"`
+	HttpPort           uint16 `default:"80"`
+	HttpServerEnabled  bool   `default:"true"`
+	MainDomain         string
+	RawDomain          string
+	PagesBranches      []string
+	AllowedCorsDomains []string
+	BlacklistedPaths   []string
+}
+
+type GiteaConfig struct {
+	Root               string
+	Token              string
+	LFSEnabled         bool   `default:"false"`
+	FollowSymlinks     bool   `default:"false"`
+	DefaultMimeType    string `default:"application/octet-stream"`
+	ForbiddenMimeTypes []string
+}
+
+type DatabaseConfig struct {
+	Type string `default:"sqlite3"`
+	Conn string `default:"certs.sqlite"`
+}
+
+type ACMEConfig struct {
+	Email             string
+	APIEndpoint       string `default:"https://acme-v02.api.letsencrypt.org/directory"`
+	AcceptTerms       bool   `default:"false"`
+	UseRateLimits     bool   `default:"true"`
+	EAB_HMAC          string
+	EAB_KID           string
+	DNSProvider       string
+	AccountConfigFile string `default:"acme-account.json"`
+}