feature: add cbfmt (#974)

Author: lukas-reineke

doc/BUILTINS.md

@@ -1939,6 +1939,23 @@ local sources = { null_ls.builtins.formatting.cabal_fmt }
 - Method: `formatting`
 - Command: `cabal-fmt`
 
+### [cbfmt](https://github.com/lukas-reineke/cbfmt)
+
+A tool to format codeblocks inside markdown and org documents.
+
+#### Usage
+
+```lua
+local sources = { null_ls.builtins.formatting.cbfmt }
+```
+
+#### Defaults
+
+- Filetypes: `{ "markdown", "org" }`
+- Method: `formatting`
+- Command: `cbfmt`
+- Args: `{ "--stdin-filepath", "$FILENAME", "--best-effort" }`
+
 ### [clang_format](https://www.kernel.org/doc/html/latest/process/clang-format.html)
 
 Tool to format C/C++/… code according to a set of rules and heuristics.

lua/null-ls/builtins/_meta/filetype_map.lua

@@ -205,7 +205,7 @@ return {
   markdown = {
     code_actions = { "proselint" },
     diagnostics = { "alex", "markdownlint", "mdl", "proselint", "vale", "write_good" },
-    formatting = { "markdownlint", "mdformat", "prettier", "prettier_d_slim", "prettierd", "remark", "terrafmt" },
+    formatting = { "markdownlint", "mdformat", "prettier", "prettier_d_slim", "prettierd", "remark", "terrafmt", "cbfmt" },
     hover = { "dictionary" }
   },
   matlab = {
@@ -222,6 +222,9 @@ return {
     diagnostics = { "deadnix", "statix" },
     formatting = { "alejandra", "nixfmt", "nixpkgs_fmt" }
   },
+  org = {
+    formatting = { "cbfmt" }
+  },
   pascal = {
     formatting = { "ptop" }
   },

lua/null-ls/builtins/_meta/formatting.lua

@@ -43,6 +43,9 @@ return {
   cabal_fmt = {
     filetypes = { "cabal" }
   },
+  cbfmt = {
+    filetypes = { "markdown", "org" }
+  },
   clang_format = {
     filetypes = { "c", "cpp", "cs", "java", "cuda" }
   },

lua/null-ls/builtins/formatting/cbfmt.lua

@@ -0,0 +1,24 @@
+local h = require("null-ls.helpers")
+local methods = require("null-ls.methods")
+
+local FORMATTING = methods.internal.FORMATTING
+
+return h.make_builtin({
+    name = "cbfmt",
+    meta = {
+        url = "https://github.com/lukas-reineke/cbfmt",
+        description = "A tool to format codeblocks inside markdown and org documents.",
+    },
+    method = FORMATTING,
+    filetypes = { "markdown", "org" },
+    generator_opts = {
+        command = "cbfmt",
+        args = {
+            "--stdin-filepath",
+            "$FILENAME",
+            "--best-effort",
+        },
+        to_stdin = true,
+    },
+    factory = h.formatter_factory,
+})