zlib-flate: add page (#7839)

pages/common/zlib-flate.md

@@ -0,0 +1,17 @@
+# zlib-flate
+
+> Raw zlib compression and decompression program.
+> Part of `qpdf`.
+> More information: <https://manned.org/zlib-flate>.
+
+- Compress a file:
+
+`zlib-flate -compress < {{path/to/input_file}} > {{path/to/compressed.zlib}}`
+
+- Uncompress a file:
+
+`zlib-flate -uncompress < {{path/to/compressed.zlib}} > {{path/to/output_file}}`
+
+- Compress a file with a specified compression level. 0=Fastest (Worst), 9=Slowest (Best):
+
+`zlib-flate -compress={{compression_level}} < {{path/to/input_file}} > {{path/to/compressed.zlib}}`