doc: Periodic grammarcheck of documentation. * doc/interpreter/basics.txi, doc/interpreter/expr.txi, doc/interpreter/install.txi, doc/interpreter/java.txi, doc/interpreter/plot.txi, doc/interpreter/sparse.txi, doc/interpreter/vectorize.txi, libinterp/corefcn/cellfun.cc, libinterp/corefcn/debug.cc, libinterp/corefcn/file-io.cc, libinterp/corefcn/load-save.cc, libinterp/corefcn/matrix_type.cc, libinterp/corefcn/pr-output.cc, libinterp/parse-tree/oct-parse.in.yy, liboctave/numeric/LSODE-opts.in, scripts/image/imformats.m, scripts/image/imread.m, scripts/image/imwrite.m, scripts/miscellaneous/error_ids.m, scripts/miscellaneous/fileattrib.m, scripts/miscellaneous/mex.m, scripts/miscellaneous/mkoctfile.m, scripts/miscellaneous/warning_ids.m, scripts/prefs/prefdir.m, scripts/prefs/preferences.m, scripts/signal/fftfilt.m, scripts/strings/isstrprop.m, scripts/testfun/assert.m: Periodic grammarcheck of documentation.

--- a/scripts/image/imformats.m
+++ b/scripts/image/imformats.m
@@ -34,18 +34,25 @@
 ## @item ext
 ## The name of the file format.  This may match the file extension but Octave
 ## will automatically detect the file format.
+##
 ## @item description
 ## A long description of the file format.
+##
 ## @item @nospell{isa}
 ## A function handle to confirm if a file is of the specified format.
+##
 ## @item write
 ## A function handle to write if a file is of the specified format.
+##
 ## @item read
 ## A function handle to open files the specified format.
+##
 ## @item info
 ## A function handle to obtain image information of the specified format.
+##
 ## @item alpha
 ## Logical value if format supports alpha channel (transparency or matte).
+##
 ## @item multipage
 ## Logical value if format supports multipage (multiple images per file).
 ## @end table