Update basic flags section in readme

Reword and mention -m flag.

README.org

@@ -46,9 +46,9 @@ alt + s
 The positional argument should be the name of a program in =$PATH= (as opposed to the full path to a program) and should not contain any flags (see =-f= if you want to pass additional flags to the program when running it).
 
 ** Basic Flags
-=-s= / =--session= should only be used for supported terminals and if the user wants to start a tmux or tmuxinator session. =-a= / =--auto-detect-wm= should be used to automatically set certain options (=-l=, =-L=, =-d=, and/or =-i=) based on the current window manager. These flags (whether automatically or manually set) may be necessary for tdrop to behave correctly (e.g. they are required for =-w= / =--width=, =-h= / =--height=, =-x= / =--xoff=, and =-y= / =--yoff= to work correctly on tiling window managers). See the manpage for these flags for specific details.
+=-s= / =--session= should only be used for supported terminals and if the user wants to start/attach to a tmux or tmuxinator session. =-a= / =--auto-detect-wm= can be specified to automatically set certain options (=-l=, =-L=, =-d=, and/or =-i=) based on the current window manager. These flags (whether automatically or manually set) may be necessary for tdrop to behave correctly (e.g. they are required for =-w= / =--width=, =-h= / =--height=, =-x= / =--xoff=, and =-y= / =--yoff= to work correctly on tiling window managers). =-m= can be specified to automatically resize the dropdown based on the current monitor's size when percentages are used for =-w= and/or =-h=. See the manpage for further details about these flags.
 
-Tdrop has basic checks to print errors for malformed commands (for example to require one positional argument). If a tdrop command does not work, please run it in a terminal or check =/tmp/tdrop/log= for error messages and consult the manpage before making an issue. For more information, see the [[#troubleshooting][Troubleshooting]] section.
+Tdrop has basic checks to print errors for malformed commands (e.g. to require one positional argument). If a tdrop command does not work, please run it in a terminal or check =/tmp/tdrop/log= for error messages and consult the manpage before making an issue. For more information, see the [[#troubleshooting][Troubleshooting]] section.
 
 *** Changes
 Long options can now be used with whitespace instead of requiring a ~=~ (i.e. =--long-opt value= and ~--long-opt=value~ are both fine).