Keybindings and smaller ui related improvements

Options:

- lualine shows path of files
- added breadcrumbs to programming buffers as winbar

Plugins:

- added mrcjkb/rustaceanvim for improved rust support
- added lewis6991/gitsigns.nvim to show changes in files
- dropped lspkind, it had no visible effect and could not easily be
  fixed
- added j-hui/fidget.nvim to make $/progress messages (e.g. from lsp)
  visible

Keybindings:

- dropped unused and commented out keybindings
- <leader>fr to resume last fzf search
- <C-W>0, 1, 2, 3 to mimic emacs <C-x>.... window keys
- <esc><esc> to clear last search
- added desc field to many keybindings in lsp

lua/plugins.lua

@@ -12,17 +12,10 @@ end
 vim.opt.rtp:prepend(lazypath)
 
 require("lazy").setup({
-  -- Vscode-like pictograms
-  {
-    "onsails/lspkind.nvim",
-    event = { "VimEnter" },
-  },
-
   -- Auto-completion engine
   {
     "hrsh7th/nvim-cmp",
     dependencies = {
-      "lspkind.nvim",
       "hrsh7th/cmp-nvim-lsp",     -- lsp auto-completion
       "hrsh7th/cmp-buffer",       -- buffer auto-completion
       "hrsh7th/cmp-path",         -- path auto-completion
@@ -49,6 +42,16 @@ require("lazy").setup({
   "williamboman/mason.nvim",
   "williamboman/mason-lspconfig.nvim",
   "neovim/nvim-lspconfig",
+
+  -- Nice plugin to show what LSPs are doing in the background (and others
+  -- using $/progress and vim.notify())
+  {
+    "j-hui/fidget.nvim",
+    opts = {
+      -- options
+    },
+  },
+
   -- show lsp signature while coding
   {
     "ray-x/lsp_signature.nvim",
@@ -94,6 +97,9 @@ require("lazy").setup({
     end,
   },
 
+  -- comfortable table editing, esp. used in orgmode
+  { 'dhruvasagar/vim-table-mode' },
+
   -- fzf-lua
   {
     "ibhagwan/fzf-lua",
@@ -107,7 +113,7 @@ require("lazy").setup({
     end
   },
 
-  -- whichkey
+  -- which-key
   {
     "folke/which-key.nvim",
     event = "VeryLazy",
@@ -161,6 +167,34 @@ require("lazy").setup({
     'nvim-lualine/lualine.nvim',
     dependencies = { 'nvim-tree/nvim-web-devicons' },
     config = function()
+      -- an alternative might be:
+      -- https://github.com/nvim-treesitter/nvim-treesitter-context
+      local function breadcrumb()
+        local result = require 'nvim-treesitter'.statusline(
+          {
+            type_patterns = {
+              "class",
+              "impl",
+              "function",
+              "method",
+              "import",
+              "for",
+              "if",
+              "while",
+              "variable",
+              "comment",
+            },
+            separator = " ▶ "
+          }
+        )
+        if result == "" then
+          result = ' '
+        elseif result == nil then
+          result = ''
+        end
+        return result
+      end
+
       require("lualine").setup {
         options = {
           icons_enabled = false,
@@ -181,7 +215,7 @@ require("lazy").setup({
           }
         },
         sections = {
-          lualine_a = { 'filename' },
+          lualine_a = { { 'filename', path = 1, shorting_target = 50 } },
           lualine_b = { 'branch', 'diff', 'diagnostics' },
           lualine_c = {},
           lualine_x = { 'encoding', 'fileformat', 'filetype' },
@@ -189,16 +223,25 @@ require("lazy").setup({
           lualine_z = { 'progress', 'location' }
         },
         inactive_sections = {
-          lualine_a = {},
+          lualine_a = { { 'filename', path = 1, shorting_target = 50 } },
           lualine_b = {},
-          lualine_c = { 'filename' },
-          lualine_x = { 'location' },
-          lualine_y = {},
-          lualine_z = {}
+          lualine_c = {},
+          -- lualine_x = { 'encoding', 'fileformat', 'filetype' },
+          lualine_x = {},
+          lualine_y = { 'filesize' },
+          lualine_z = { 'location' }
         },
         tabline = {},
-        winbar = {},
-        inactive_winbar = {},
+        winbar = {
+          lualine_a = {
+            { breadcrumb,
+              color = { bg = '#101010', fg = '#568200' },
+            },
+          },
+        },
+        inactive_winbar = {
+          lualine_a = { breadcrumb },
+        },
         extensions = {}
       }
     end
@@ -247,9 +290,6 @@ require("lazy").setup({
     "PhilRunninger/cmp-rpncalc",
   },
 
-  -- comfortable table editing, esp. used in orgmode
-  { 'dhruvasagar/vim-table-mode' },
-
   -- TODO, WARN, HACK, PERF, NOTE, TEST and others highlighting and searching
   {
     "folke/todo-comments.nvim",
@@ -275,8 +315,8 @@ require("lazy").setup({
   { "cpkio/nvim-treesitter-asciidoc" },
 
 
+  -- Greeter to run on NeoVim startup
   {
-
     'goolord/alpha-nvim',
     dependencies = {
       'nvim-tree/nvim-web-devicons',
@@ -384,5 +424,18 @@ require("lazy").setup({
     end,
   },
 
+  -- improved Rust support
+  {
+    'mrcjkb/rustaceanvim',
+    version = '^5', -- Recommended
+    lazy = false,   -- This plugin is already lazy
+  },
 
+  -- show git changes on the left
+  {
+    "lewis6991/gitsigns.nvim",
+    config = function()
+      require('gitsigns').setup()
+    end,
+  },
 })