DOC: add documentation for rotate subcommand

Issue: #95

Author: moormaster

docs/index.rst

@@ -24,6 +24,7 @@ pdfly is a command line tool to get information about PDF documents and to manip
    user/subcommand-extract-text
    user/subcommand-compress
    user/subcommand-uncompress
+   user/subcommand-rotate
    user/subcommand-update-offsets
 
 

docs/user/subcommand-rotate.md

@@ -0,0 +1,71 @@
+# rotate
+
+## Usage
+
+```
+pdfly rotate --help
+
+ Usage: pdfly rotate [OPTIONS] FILENAME DEGREES [PGRGS]
+
+ Rotate specified pages by the specified amount
+
+ Example:
+     pdfly rotate --output output.pdf input.pdf 90
+         Rotate all pages by 90 degrees (clockwise)
+
+ A file not followed by a page range (PGRGS) means all the pages of the file.
+
+ PAGE RANGES are like Python slices.
+
+         Remember, page indices start with zero.
+
+         Page range expression examples:
+
+             :     all pages.                   -1    last page.
+             22    just the 23rd page.          :-1   all but the last page.
+             0:3   the first three pages.       -2    second-to-last page.
+             :3    the first three pages.       -2:   last two pages.
+             5:    from the sixth page onward.  -3:-1 third & second to last.
+
+         The third, "stride" or "step" number is also recognized.
+
+             ::2       0 2 4 ... to the end.    3:0:-1    3 2 1 but not 0.
+             1:10:2    1 3 5 7 9                2::-1     2 1 0.
+             ::-1      all pages in reverse order.
+
+╭─ Arguments ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
+│ *    filename      FILE     [required]                                                                                                                                                     │
+│ *    degrees       INTEGER  degrees to rotate [required]                                                                                                                                   │
+│      pgrgs         [PGRGS]  page range [default: :]                                                                                                                                        │
+╰────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
+╭─ Options ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
+│ *  --output  -o      PATH  [required]                                                                                                                                                      │
+│    --help                  Show this message and exit.                                                                                                                                     │
+╰────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
+```
+
+## Examples
+
+### Rotate all pages by 90 degrees (clockwise)
+
+Rotate all pages from `input.pdf` by 90 degrees (clockwise) and write the resulting pdf to `output.pdf`.
+
+```
+pdfly rotate --output output.pdf input.pdf 90
+```
+
+### Rotate first three pages by 90 degrees (clockwise)
+
+Rotate first three pages from `input.pdf` by 90 degrees (clockwise) and write the resulting pdf to `output.pdf`.
+
+```
+pdfly rotate --output output.pdf input.pdf 90 :3
+```
+
+### Rotate last page by 90 degrees (clockwise)
+
+Rotate last page from `input.pdf` by 90 degrees (clockwise) and write the resulting pdf to `output.pdf`.
+
+```
+pdfly rotate --output output.pdf input.pdf 90 -- -1
+```