Remove vim-projectionist

I've replaced it with edit_alternate.vim in the previous commit, which
works with `.twig` and `.config.yml` files in Fractal projects as well
as test classes in Drupal, which is all I need alternate files for at
the moment.

lib/default.nix

@@ -71,7 +71,6 @@ rec {
       vimPlugins.vim-highlightedyank
       vimPlugins.vim-just
       vimPlugins.vim-nix
-      vimPlugins.vim-projectionist
       vimPlugins.nvim-spectre
       vimPlugins.vim-autoread
       vimPlugins.vim-obsession

plugin/projectionist.lua

@@ -1,57 +0,0 @@
-vim.g.projectionist_heuristics = {
-  ["composer.json"] = {
-    ["src/*.php"] = {
-      type = "source",
-      alternate = "tests/{}Test.php",
-    },
-
-    ["src/Controller/*.php"] = {
-      type = "controller",
-    },
-
-    ["src/Model/*.php"] = {
-      type = "model",
-    },
-
-    ["src/Service/*.php"] = {
-      type = "service",
-    },
-
-    ["tests/*Test.php"] = {
-      type = "test",
-      alternate = "src/{}.php",
-    },
-  },
-
-  ["fractal.config.js"] = {
-    ["*.config.yml"] = {
-      type = "config",
-      alternate = "{dirname}/{basename}.twig",
-    },
-
-    ["*.twig"] = {
-      type = "template",
-      alternate = "{dirname}/{basename}.config.yml",
-    },
-  },
-
-  ["package.json"] = {
-    ["src/*.ts"] = {
-      type = "source",
-      alternate = "tests/{}.test.ts",
-    },
-
-    ["src/*.service.ts"] = {
-      type = "source",
-      alternate = "tests/{}.test.ts",
-    },
-
-    ["tests/*.test.ts"] = {
-      type = "test",
-      alternate = "src/{}.ts",
-    },
-  },
-}
-
--- Switch to an alternative file.
-vim.keymap.set("n", "<leader>aa", "<cmd>A<cr>")