doc: Spelling fixes

Correct typos of the following word families:

transparent
roughly

ASTERISK-29714

Change-Id: I2b90c68dfde4aa3f0d58f64f8187465336acb1b3

doc/asterisk-ng-doxygen.in

@@ -283,7 +283,7 @@ TYPEDEF_HIDES_STRUCT   = NO
 # causing a significant performance penality.
 # If the system has enough physical memory increasing the cache will improve the
 # performance by keeping more symbols in memory. Note that the value works on
-# a logarithmic scale so increasing the size by one will rougly double the
+# a logarithmic scale so increasing the size by one will roughly double the
 # memory usage. The cache size is given by this formula:
 # 2^(16+SYMBOL_CACHE_SIZE). The valid range is 0..9, the default is 0,
 # corresponding to a cache size of 2^16 = 65536 symbols
@@ -1062,7 +1062,7 @@ EXT_LINKS_IN_WINDOW    = NO
 
 FORMULA_FONTSIZE       = 10
 
-# Use the FORMULA_TRANPARENT tag to determine whether or not the images
+# Use the FORMULA_TRANSPARENT tag to determine whether or not the images
 # generated for formulas are transparent PNGs. Transparent PNGs are
 # not supported properly for IE 6.0, but are supported on all modern browsers.
 # Note that when changing this option you need to delete any form_*.png files