Move lsp config to local file structure

.config/nvim/lsp/solang.lua

@@ -0,0 +1,19 @@
+---@brief
+---
+---A language server for Solidity
+---
+--- See the [documentation](https://solang.readthedocs.io/en/latest/installing.html) for installation instructions.
+---
+--- The language server only provides the following capabilities:
+--- * Syntax highlighting
+--- * Diagnostics
+--- * Hover
+---
+--- There is currently no support for completion, goto definition, references, or other functionality.
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'solang', 'language-server', '--target', 'evm' },
+  filetypes = { 'solidity' },
+  root_markers = { '.git' },
+}