Enable the vale linter also for further markup languages (#1230)

* Enable the vale linter also for LaTeX
* Enable the vale linter for rst files

ale_linters/rst/vale.vim

@@ -0,0 +1,9 @@
+" Author: chew-z https://github.com/chew-z
+" Description: vale for RST files
+
+call ale#linter#Define('rst', {
+\   'name': 'vale',
+\   'executable': 'vale',
+\   'command': 'vale --output=JSON %t',
+\   'callback': 'ale#handlers#vale#Handle',
+\})

ale_linters/tex/vale.vim

@@ -0,0 +1,9 @@
+" Author: chew-z https://github.com/chew-z
+" Description: vale for LaTeX files
+
+call ale#linter#Define('tex', {
+\   'name': 'vale',
+\   'executable': 'vale',
+\   'command': 'vale --output=JSON %t',
+\   'callback': 'ale#handlers#vale#Handle',
+\})