Merge pull request 'FIX: mime-type not reflecting file extension, update README' (#7) from supitszaire/indir:main into main

Reviewed-on: https://codeberg.org/arimelody/indir/pulls/7

README.md

@@ -16,7 +16,17 @@ indir [--host address] [--port port] [--root http_root] directory
     --root http_root    hosts on the specified subdirectory, i.e. `/files/`
 ```
 
+## customization
+
+### readme
+drop a `README.md` into any directory and indir will render
+it below the file listing with full markdown support!
+
+---
+
 ## to-do:
 - [x] use templates instead of hard-coded HTML (i was lazy)
-- [ ] directory header from readme file
+- [x] directory header from readme file
 - [ ] directory stylesheet overrides
+- [x] index.html serving support
+- [x] fix mime-types for browser file view

main.go

@@ -154,7 +154,9 @@ func main() {
 			mimeType := "application/octet-stream"
 			extPos := strings.LastIndex(info.Name(), ".")
 			if extPos != -1 {
-				mimeType = mime.TypeByExtension(info.Name()[:extPos])
+				if m := mime.TypeByExtension(info.Name()[extPos:]); m != "" {
+					mimeType = m
+				}
 			}
 
 			w.Header().Set("Content-Type", mimeType)