Add healthcheck

- Checks that jj is installed
- Checks that jj version is supported

lua/telescope/_extensions/jj.lua

@@ -9,4 +9,21 @@ return telescope.register_extension({
         -- access extension config and user config
     end,
     exports = require("telescope-jj"),
+    health = function()
+        if vim.fn.executable("jj") == 1 then
+            vim.health.ok("jj installed")
+        end
+
+        local obj = vim.system({ "jj", "--version" }, { text = true }):wait()
+        for major, minor, patch in string.gmatch(obj.stdout, ".*(%d+).(%d+).(%d+)") do
+            if not (tonumber(major) == 0 and tonumber(minor) >= 19) then
+                vim.health.warn("requires jj version 0.19.0 or greater")
+                vim.health.info("found jj version: " .. major .. "." .. minor .. "." .. patch)
+            else
+                vim.health.ok(
+                    "jj version " .. major .. "." .. minor .. "." .. patch .. " is supported"
+                )
+            end
+        end
+    end,
 })