Upgrade clap to v4

Cargo.lock

@@ -181,6 +181,29 @@ dependencies = [
  "vec_map",
 ]
 
+[[package]]
+name = "clap"
+version = "4.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0a1af219c3e254a8b4649d6ddaef886b2015089f35f2ac5e1db31410c0566ab8"
+dependencies = [
+ "atty",
+ "bitflags",
+ "clap_lex",
+ "once_cell",
+ "strsim 0.10.0",
+ "termcolor",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d4198f73e42b4936b35b5bb248d81d2b595ecb170da0bac7655c54eedfa8da8"
+dependencies = [
+ "os_str_bytes",
+]
+
 [[package]]
 name = "clearscreen"
 version = "1.0.10"
@@ -881,7 +904,7 @@ dependencies = [
 name = "md2pdf"
 version = "0.0.1"
 dependencies = [
- "clap",
+ "clap 4.0.7",
  "pulldown-cmark",
  "tectonic",
 ]
@@ -1144,6 +1167,12 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "os_str_bytes"
+version = "6.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ff7415e9ae3fff1225851df9e0d9e4e5479f947619774677a63572e55e80eff"
+
 [[package]]
 name = "pathdiff"
 version = "0.2.1"
@@ -1559,7 +1588,7 @@ version = "0.3.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c6b5c64445ba8094a6ab0c3cd2ad323e07171012d9c98b0b15651daf1787a10"
 dependencies = [
- "clap",
+ "clap 2.34.0",
  "lazy_static",
  "structopt-derive",
 ]