Fix typo in [ |SYN_OPT-V| ] and correct -T option syntax (#8811)

Author: Chuan1937

doc/rst/source/supplements/gsfml/mlconverter.rst

@@ -16,8 +16,8 @@ Synopsis
 [ |-A| ]
 [ |-G|\ [**s**] ]
 [ |-I|\ *FZid* ] 
-[ |-T|\ **c**\ |\ **g**\ |\ **o**\ |\ **s** ]
-[ GMT_V_OPT ]
+[ |-T|\ **c**\|\ **g**\|\ **o**\|\ **s** ]
+[ |SYN_OPT-V| ]
 
 |No-spaces|
 
@@ -51,7 +51,7 @@ Optional Arguments
 
 .. _-T:
 
-**-Tc**\ |\ **g**\ |\ **o**\ |\ **s**
+**-T**\ **c**\|\ **g**\|\ **o**\|\ **s**
     Select the magnetic time scale to use.  Choose from **c** (Cande and Kent, 1995),
     **g** (Gee and Kent, 2007), **o** (Ogg, 2012), or **s** (Gradstein, 2004) [**g**].