screenshot: Replace image with png crate

Cargo.lock

@@ -33,6 +33,12 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "adler32"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aae1277d39aeec15cb388266ecc24b11c80469deae6067e17a1a7aa9e5c1f234"
+
 [[package]]
 name = "ahash"
 version = "0.7.6"
@@ -301,6 +307,7 @@ dependencies = [
  "indexmap",
  "lazy_static",
  "libsystemd",
+ "png",
  "regex",
  "ron",
  "sendfd",
@@ -342,6 +349,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "crc32fast"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b540bd8bc810d3885c6ea91e2018302f68baba2129ab3e88f32389ee9370880d"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "crossbeam-channel"
 version = "0.5.6"
@@ -413,6 +429,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "deflate"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c86f7e25f518f4b81808a2cf1c50996a61f5c2eb394b2393bd87f2a4780a432f"
+dependencies = [
+ "adler32",
+]
+
 [[package]]
 name = "digest"
 version = "0.10.3"
@@ -1169,6 +1194,18 @@ version = "0.3.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1df8c4ec4b0627e53bdf214615ad287367e482558cf84b109250b37464dc03ae"
 
+[[package]]
+name = "png"
+version = "0.17.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc38c0ad57efb786dd57b9864e5b18bae478c00c824dc55a38bbc9da95dde3ba"
+dependencies = [
+ "bitflags",
+ "crc32fast",
+ "deflate",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.16"