[nvim] Add gitlens, scratchfile lua plugins

Added gitlens to show git blame for cursorline after short time. Added
makescratch plugin to create a new scratch window via simple command.

nvim/.config/nvim/plugin/personal/gitlens.vim

@@ -0,0 +1,23 @@
+function s:setupGitLens()
+  " -- disable gitlens unconditionally, and remove virtual text
+  lua require('gitlens').clearBlameVirtText()
+  augroup GitLens
+    autocmd!
+  augroup END
+
+  " -- if it is wanted enable gitlens on holding the cursor
+  if g:gitlens_enable
+    augroup GitLens
+      autocmd! CursorHold * lua require('gitlens').blameVirtText()
+      autocmd! CursorMoved * lua require('gitlens').clearBlameVirtText()
+      autocmd! CursorMovedI * lua require('gitlens').clearBlameVirtText()
+    augroup END
+  endif
+endfunction
+
+function s:toggleGitLens()
+  let g:gitlens_enable = !get(g:, 'gitlens_enable', 1)
+  call s:setupGitLens()
+endfunction
+
+command! GitLensToggle call s:toggleGitLens()

nvim/.config/nvim/plugin/personal/makescratch.vim

@@ -0,0 +1,5 @@
+function s:makeScratch()
+  lua require('scratchpad').makeScratch()
+endfunction
+
+command! ScratchPad call s:makeScratch()