all: various improvements

README.md

@@ -1,6 +1,6 @@
 # fdup
 
-The dumb tool to find duplicate files by it's hash sums.
+The dumb tool for finding duplicate files by their hash sums.
 
 Compile it with `-prod` for better performance:
 
@@ -13,14 +13,20 @@ Look at releases page for prebuilt executables.
 # Synonsis
 
 ```
-Usage: fdup [flags] [commands] [path...]
+Usage: fdup [flags] [commands] [DIR...]
 
 File duplicates finder
 
 Flags:
-  -hash               Set hashing algorythm: blake3, sha1, sha256, md5 [default: md5]
+  -hash               Hashing algorythm: blake3, crc32, fnv1a, sha1, sha256, md5 [default: fnv1a]
   -threads            Number of threads used for calculating hash sums [default: number of CPU cores]
-  -brief              Brief output, print plain easy to parse hashes and filenames only
+  -brief              Brief output, print plain easy to parse hashes and filenames only.
+  -json               Print output in JSON format.
+  -exclude            Glob pattern to exclude files and directories [can be passed multiple times]
+  -skip-empty         Skip empty files.
+  -max-size           Maximum file size in bytes. Files larger than this will be skipped.
+  -remove             Remove duplicates.
+  -prompt             Prompt before every removal.
   -help               Prints help information.
   -version            Prints version information.