feat(lang): add solidity language support

## Description

- Add Solidity language support to `nvim-treesitter` for syntax highlighting and enhanced code understanding.
- Configure `nvim-lspconfig` for Solidity LSP support, setting up `solidity_ls` with a root pattern detection for Solidity projects.
- Integrate `forge_fmt` as the formatter for Solidity files using `conform.nvim`, with command options for `forge fmt`.

lua/lazyvim/plugins/extras/lang/solidity.lua

@@ -0,0 +1,47 @@
+return {
+  recommended = function()
+    return LazyVim.extras.wants({
+      ft = "solidity",
+      root = {
+        "foundry.toml",
+        "hardhat.config.js",
+        "hardhat.config.ts",
+      },
+    })
+  end,
+  -- Add Solidity & related to treesitter
+  {
+    "nvim-treesitter/nvim-treesitter",
+    opts = { ensure_installed = { "solidity" } },
+  },
+
+  -- Correctly setup lspconfig for Solidity
+  {
+    "neovim/nvim-lspconfig",
+    opts = {
+      servers = {
+        solidity_ls = {
+          filetypes = { "solidity" },
+          root_dir = function(fname)
+            return require("lspconfig").util.root_pattern("foundry.toml", "hardhat.config.*", ".git")(fname)
+          end,
+        },
+      },
+    },
+  },
+  -- Formatter for Solidity
+  {
+    "conform.nvim",
+    opts = function(_, opts)
+      opts.formatters_by_ft = opts.formatters_by_ft or {}
+      opts.formatters_by_ft.solidity = { "forge_fmt" }
+
+      opts.formatters = {
+        forge_fmt = {
+          command = "forge",
+          args = { "fmt" },
+        },
+      }
+    end,
+  },
+}