Added builtins/__modules.lua

Script defines all tools available by presser.nvim, which are
lazy-loaded and executed when called by the user.

Function presser@find_replace has undergone major refactorisation:
	- Keymaps have been updated to respect new codebase structure.
	- A new OOP implementation is being experimented for constructing
	  windows, giving future flexibility. Consult presser/steamers.lua.
	- Function now calls the class@streamers and invokes the
	  streamers@new() method. This constructs the windows/buffers which
	  was originally done via call to presser@new().
	- This function is NOT directly accessed, but via proxy
	  table@builtins which lazy-loads function.

Any new tools which are created for presser are to be defined in this
file and lazy-loaded. Module may be renamed in future for theming
consistency.

presser/builtins/__modules.lua

@@ -0,0 +1,83 @@
+local gcm = require'presser.context_manager'
+local steamers = require'presser.steamers'
+local actions = require'presser.actions'
+
+local a = vim.api
+
+local modules = {}
+
+-- @Description: Find and replace words within the current buffer.
+-- @Params:
+-- @Returns: nil.
+--
+-- @Dev: function is responsible to creating all required buffers to allow full user interaction.
+--
+-- @Future: implementation may allow for greater user customisation similar to what's found with
+-- extensions such as Telescope. For now, it should provide a concrete UI for purpose of design.
+modules.find_replace = function ()
+  -- define the context which these windows will belong to in the context manager.
+  local ctx = "find_replace"
+  gcm.create( ctx )
+  
+  local keymap = {
+    n = {
+      ["<esc>"] = "<cmd>lua require'presser.actions'.close()<CR>",
+      ["<A-a>"] = "<cmd>lua require'presser.actions'.execute()<CR>",
+    },
+    i = {
+      ["<down>"] = "<cmd>lua require'presser.actions'.move_next_buffer()<CR>",
+      ["<A-a>"] = "<cmd>lua require'presser.actions'.execute()<CR>",
+    }
+  }
+
+  -- get the centre of the current buffer
+  local c_cols = math.floor( a.nvim_win_get_width(0) / 2 )
+  local c_lines = math.floor( a.nvim_win_get_height(0) / 2 )
+
+  -- create a title buffer for the steamer
+  steamers
+    .new( ctx, {
+      label = "presser_title",
+      steamer = {
+        placeholder = "Find & Replace",
+        allowed = false,
+        window = {
+          line = c_lines - 3,
+          border = false,
+          minwidth = 82,
+          padding = { 0, 1, 1, 1 }
+        }
+      }
+    } )
+
+  -- create a new buffer for find pattern
+  steamers
+    .new ( ctx, {
+      label = "find_buf",
+      steamer = {
+        window = {
+          line = c_lines,
+          title = "Find",
+        },
+        keybinds = keymap,
+      }
+    } )
+
+  -- create a new buffer for replace pattern
+  steamers
+    .new( ctx, {
+      label = "replace_buf",
+      steamer = {
+        window = {
+          line = c_lines + 3,
+          title = "Replace",
+        },
+        keybinds = keymap,
+      }
+    } )
+
+  local result = actions.buf_put_curser_at( "find_buf" )
+  a.nvim_feedkeys('A', 'n', false)
+end
+
+return modules