Squashed commit of sync hidden files:

commit 73967756d51d246b3ca203aa3683cdfebf567000
Author: fyears <1142836+fyears@users.noreply.github.com>
Date:   Sun Mar 13 22:41:28 2022 +0800

    fix typo

commit 08e16faa9a9ace9bec71acb723e0d70ca361d49f
Author: fyears <1142836+fyears@users.noreply.github.com>
Date:   Sun Mar 13 22:41:01 2022 +0800

    add modal in settings

commit 9db7194fa28cb62b1fa4c01ac7f746d5ac3b86a8
Author: fyears <1142836+fyears@users.noreply.github.com>
Date:   Sun Mar 13 22:03:00 2022 +0800

    working sync for .obsidian and _

commit 4be24ba092181c1c3e1aabe5e9d4e9fcff28f987
Author: fyears <1142836+fyears@users.noreply.github.com>
Date:   Sun Mar 13 16:07:10 2022 +0800

    more logic for hidden path

src/sync.ts

@@ -46,6 +46,7 @@ import {
 
 import * as origLog from "loglevel";
 import { padEnd } from "lodash";
+import { isInsideObsFolder, ObsConfigDirFileType } from "./obsFolderLister";
 const log = origLog.getLogger("rs-default");
 
 export type SyncStatusType =
@@ -272,18 +273,39 @@ export const fetchMetadataFile = async (
   return metadata;
 };
 
+const isSkipItem = (
+  key: string,
+  syncConfigDir: boolean,
+  syncUnderscoreItems: boolean,
+  configDir: string
+) => {
+  if (syncConfigDir && isInsideObsFolder(key, configDir)) {
+    return false;
+  }
+  return (
+    isHiddenPath(key, true, false) ||
+    (!syncUnderscoreItems && isHiddenPath(key, false, true)) ||
+    key === DEFAULT_FILE_NAME_FOR_METADATAONREMOTE ||
+    key === DEFAULT_FILE_NAME_FOR_METADATAONREMOTE2
+  );
+};
+
 const ensembleMixedStates = async (
   remoteStates: FileOrFolderMixedState[],
   local: TAbstractFile[],
+  localConfigDirContents: ObsConfigDirFileType[] | undefined,
   remoteDeleteHistory: DeletionOnRemote[],
-  localDeleteHistory: FileFolderHistoryRecord[]
+  localDeleteHistory: FileFolderHistoryRecord[],
+  syncConfigDir: boolean,
+  configDir: string,
+  syncUnderscoreItems: boolean
 ) => {
   const results = {} as Record<string, FileOrFolderMixedState>;
 
   for (const r of remoteStates) {
     const key = r.key;
 
-    if (isHiddenPath(key)) {
+    if (isSkipItem(key, syncConfigDir, syncUnderscoreItems, configDir)) {
       continue;
     }
     results[key] = r;
@@ -316,9 +338,10 @@ const ensembleMixedStates = async (
       throw Error(`unexpected ${entry}`);
     }
 
-    if (isHiddenPath(key)) {
+    if (isSkipItem(key, syncConfigDir, syncUnderscoreItems, configDir)) {
       continue;
     }
+
     if (results.hasOwnProperty(key)) {
       results[key].key = r.key;
       results[key].existLocal = r.existLocal;
@@ -330,6 +353,28 @@ const ensembleMixedStates = async (
     }
   }
 
+  if (syncConfigDir && localConfigDirContents !== undefined) {
+    for (const entry of localConfigDirContents) {
+      const key = entry.key;
+      const r: FileOrFolderMixedState = {
+        key: key,
+        existLocal: true,
+        mtimeLocal: Math.max(entry.mtime, entry.ctime),
+        sizeLocal: entry.size,
+      };
+
+      if (results.hasOwnProperty(key)) {
+        results[key].key = r.key;
+        results[key].existLocal = r.existLocal;
+        results[key].mtimeLocal = r.mtimeLocal;
+        results[key].sizeLocal = r.sizeLocal;
+      } else {
+        results[key] = r;
+        results[key].existRemote = false;
+      }
+    }
+  }
+
   for (const entry of remoteDeleteHistory) {
     const key = entry.key;
     const r = {
@@ -337,6 +382,10 @@ const ensembleMixedStates = async (
       deltimeRemote: entry.actionWhen,
     } as FileOrFolderMixedState;
 
+    if (isSkipItem(key, syncConfigDir, syncUnderscoreItems, configDir)) {
+      continue;
+    }
+
     if (results.hasOwnProperty(key)) {
       results[key].key = r.key;
       results[key].deltimeRemote = r.deltimeRemote;
@@ -365,9 +414,10 @@ const ensembleMixedStates = async (
       deltimeLocal: entry.actionWhen,
     } as FileOrFolderMixedState;
 
-    if (isHiddenPath(key)) {
+    if (isSkipItem(key, syncConfigDir, syncUnderscoreItems, configDir)) {
       continue;
     }
+
     if (results.hasOwnProperty(key)) {
       results[key].key = r.key;
       results[key].deltimeLocal = r.deltimeLocal;
@@ -618,17 +668,25 @@ const DELETION_DECISIONS: Set<DecisionType> = new Set([
 export const getSyncPlan = async (
   remoteStates: FileOrFolderMixedState[],
   local: TAbstractFile[],
+  localConfigDirContents: ObsConfigDirFileType[] | undefined,
   remoteDeleteHistory: DeletionOnRemote[],
   localDeleteHistory: FileFolderHistoryRecord[],
   remoteType: SUPPORTED_SERVICES_TYPE,
   vault: Vault,
+  syncConfigDir: boolean,
+  configDir: string,
+  syncUnderscoreItems: boolean,
   password: string = ""
 ) => {
   const mixedStates = await ensembleMixedStates(
     remoteStates,
     local,
+    localConfigDirContents,
     remoteDeleteHistory,
-    localDeleteHistory
+    localDeleteHistory,
+    syncConfigDir,
+    configDir,
+    syncUnderscoreItems
   );
 
   const sortedKeys = Object.keys(mixedStates).sort(