use tcell via porting over code from awesome-gocui

vendor/github.com/gdamore/tcell/v2/doc.go

@@ -0,0 +1,48 @@
+// Copyright 2018 The TCell Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use file except in compliance with the License.
+// You may obtain a copy of the license at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package tcell provides a lower-level, portable API for building
+// programs that interact with terminals or consoles.  It works with
+// both common (and many uncommon!) terminals or terminal emulators,
+// and Windows console implementations.
+//
+// It provides support for up to 256 colors, text attributes, and box drawing
+// elements.  A database of terminals built from a real terminfo database
+// is provided, along with code to generate new database entries.
+//
+// Tcell offers very rich support for mice, dependent upon the terminal
+// of course.  (Windows, XTerm, and iTerm 2 are known to work very well.)
+//
+// If the environment is not Unicode by default, such as an ISO8859 based
+// locale or GB18030, Tcell can convert input and output, so that your
+// terminal can operate in whatever locale is most convenient, while the
+// application program can just assume "everything is UTF-8".  Reasonable
+// defaults are used for updating characters to something suitable for
+// display.  Unicode box drawing characters will be converted to use the
+// alternate character set of your terminal, if native conversions are
+// not available.  If no ACS is available, then some ASCII fallbacks will
+// be used.
+//
+// Note that support for non-UTF-8 locales (other than C)  must be enabled
+// by the application using RegisterEncoding() -- we don't have them all
+// enabled by default to avoid bloating the application unneccessarily.
+// (These days UTF-8 is good enough for almost everyone, and nobody should
+// be using legacy locales anymore.)  Also, actual glyphs for various code
+// point will only be displayed if your terminal or emulator (or the font
+// the emulator is using) supports them.
+//
+// A rich set of keycodes is supported, with support for up to 65 function
+// keys, and various other special keys.
+//
+package tcell