Add .editorconfig file and remove trailing newlines

beacon_chain/.editorconfig

@@ -0,0 +1,12 @@
+# https://EditorConfig.org
+root = true
+
+[*.nim]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[Makefile]
+indent_style = tab

beacon_chain/spec/datatypes/altair.nim

@@ -527,4 +527,3 @@ chronicles.formatIt SyncCommitteeMessage: shortLog(it)
 
 func hash*(x: LightClientUpdate): Hash =
   hash(x.header.state_root.data)
-

beacon_chain/spec/helpers.nim

@@ -237,4 +237,3 @@ func has_flag*(flags: ParticipationFlags, flag_index: int): bool =
 # https://github.com/ethereum/eth2.0-specs/blob/v1.1.0-beta.3/specs/altair/sync-protocol.md#get_subtree_index
 func get_subtree_index*(idx: GeneralizedIndex): uint64 =
   uint64(idx mod (type(idx)(1) shl log2trunc(idx)))
-