feat(nvim): reworked lsp, theme, cleanup

Signed-off-by: Ismo Vuorinen <ismo@ivuorinen.net>

config/nvim/syntax/env.vim

@@ -0,0 +1,31 @@
+" Vim syntax file
+" Language:   env files (NOT shell code)
+" Maintainer: Gernot Schulz <gernot.schulz@overleaf.com>
+" Source:     https://github.com/overleaf/vim-env-syntax
+
+" quit when a syntax file was already loaded
+if exists("b:current_syntax")
+  finish
+endif
+
+syn match  envComment                   '^#.*'
+syn match  envVariableUnassigned        "^\<\h\w*$"
+
+syn match  envVariable                  "^\<\h\w*\ze="  nextgroup=envVarAssign
+syn match  envVarAssign     contained   "="             nextgroup=envVar,envQuotedVarOpen,envSpace
+syn match  envVar           contained   "\h\w*"
+syn match  envSpace         contained   "\s\+"          nextgroup=envQuotedVarOpen
+syn match  envQuotedVarOpen contained   "[\"']"
+
+syn match  envSpace                     "\s$"
+syn match  envQuotedVarClose            "[\"']$"
+
+let b:current_syntax = "env"
+
+hi def link envComment            Comment
+hi def link envVariableUnassigned Error
+hi def link envVariable           Identifier
+hi def link envVarAssign          Operator
+hi def link envSpace              Error
+hi def link envQuotedVarOpen      Error
+hi def link envQuotedVarClose     Error