Add /upstream endpoint (#30)

* remove catch-all route to upstream proxy (it was broken anyways)
* add /upstream/:model_id to swap and route to upstream path
* add /upstream HTML endpoint and unlisted option
* add /upstream endpoint to show a list of available models
* add `unlisted` configuration option to omit a model from /v1/models and /upstream lists
* add favicon.ico

proxy/proxymanager_loghandlers.go

@@ -1,7 +1,6 @@
 package proxy
 
 import (
-	"embed"
 	"fmt"
 	"net/http"
 	"strings"
@@ -9,12 +8,6 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-//go:embed html/logs.html
-var logsHTML []byte
-
-// make sure embed is kept there by the IDE auto-package importer
-var _ = embed.FS{}
-
 func (pm *ProxyManager) sendLogsHandlers(c *gin.Context) {
 
 	accept := c.GetHeader("Accept")