Add openscad and sca2d support (#4205)

ale_linters/openscad/sca2d.vim

@@ -0,0 +1,24 @@
+" Description: SCA2D linter for OpenSCAD files
+
+call ale#Set('openscad_sca2d_executable', 'sca2d')
+call ale#Set('openscad_sca2d_options', '')
+
+function! ale_linters#openscad#sca2d#GetExecutable(buffer) abort
+    return ale#Var(a:buffer, 'openscad_sca2d_executable')
+endfunction
+
+function! ale_linters#openscad#sca2d#GetCommand(buffer) abort
+    let l:executable = ale_linters#openscad#sca2d#GetExecutable(a:buffer)
+    let l:options = ale#Var(a:buffer, 'openscad_sca2d_options')
+
+    return ale#Escape(l:executable) . ale#Pad(l:options) . ' %s'
+endfunction
+
+call ale#linter#Define('openscad', {
+\ 'name': 'SCA2D',
+\ 'aliases': ['sca2d'],
+\ 'executable': function('ale_linters#openscad#sca2d#GetExecutable'),
+\ 'command': function('ale_linters#openscad#sca2d#GetCommand'),
+\ 'callback': 'ale#handlers#openscad#SCA2D_callback',
+\ 'lint_file': 1,
+\ })