Lower level for edoc log message from ERROR to DEBUG

[robertoaloi]

A sample message:

[2021-11-24T09:02:36.464478+01:00] [error] [hover] Error fetching edoc [error={my_parse_transform,process_form,1,error,{badmatch,{not_found,<<"Item description is not available.\n">>}},[{els_docs,edoc,3,[{file,"/Users/robert.aloi/git/github/erlang-ls/erlang_ls/apps/els_lsp/src/els_docs.erl"},{line,346}]},{els_docs,function_docs,4,[{file,"/Users/robert.aloi/git/github/erlang-ls/erlang_ls/apps/els_lsp/src/els_docs.erl"},{line,101}]},{els_hover_provider,do_get_docs,2,[{file,"/Users/robert.aloi/git/github/erlang-ls/erlang_ls/apps/els_lsp/src/els_hover_provider.erl"},{line,97}]},{els_background_job,handle_info,2,[{file,"/Users/robert.aloi/git/github/erlang-ls/erlang_ls/apps/els_lsp/src/els_background_job.erl"},{line,160}]},{gen_server,try_dispatch,4,[{file,"gen_server.erl"},{line,680}]},{gen_server,handle_msg,6,[{file,"gen_server.erl"},{line,756}]},{proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,226}]}],[]}] [els_docs:edoc/3 L350] <0.13598.0>