zstd, unzstd: update page; zstd{cat,mt}: add alias page (#10683)

pages/common/unzstd.md

@@ -1,16 +1,7 @@
 # unzstd
 
-> Decompress files with Zstandard compression.
-> More information: <https://github.com/facebook/zstd>.
+> This command is an alias of `zstd --decompress`.
 
-- Decompress files:
+- View documentation for the original command:
 
-`unzstd {{path/to/file1.ztd path/to/file2.ztd ...}}`
-
-- Decompress a file into a specific output file:
-
-`unzstd {{path/to/compressed.ztd}} -o {{path/to/extracted_file}}`
-
-- Display information about a compressed file:
-
-`unzip --list {{path/to/file.zst}}`
+`tldr zstd`

pages/common/zstd.md

@@ -9,11 +9,11 @@
 
 - Decompress a file:
 
-`zstd -d {{path/to/file}}.zst`
+`zstd --decompress {{path/to/file.zst}}`
 
 - Decompress to `stdout`:
 
-`zstd -dc {{path/to/file}}.zst`
+`zstd --decompress --stdout {{path/to/file.zst}}`
 
 - Compress a file specifying the compression level, where 1=fastest, 19=slowest and 3=default:
 

pages/common/zstdcat.md

@@ -0,0 +1,7 @@
+# zstdcat
+
+> This command is an alias of `zstd --decompress --stdout`.
+
+- View documentation for the original command:
+
+`tldr zstd`

pages/common/zstdmt.md

@@ -0,0 +1,7 @@
+# zstdmt
+
+> This command is an alias of `zstd --threads 0` (which sets the number of working threads to the number of physical CPU cores).
+
+- View documentation for the original command:
+
+`tldr zstd`