updated README.

README.md

@@ -1,6 +1,52 @@
+# A diary for everyone
+
 [![Calendar build](https://github.com/k-l-lambda/diary-one/actions/workflows/calendar.yml/badge.svg)](https://github.com/k-l-lambda/diary-one/actions/workflows/calendar.yml)
 [![Cowriter](https://github.com/k-l-lambda/diary-one/actions/workflows/cowriter.yml/badge.svg)](https://github.com/k-l-lambda/diary-one/actions/workflows/cowriter.yml)
 [![Statistics](https://github.com/k-l-lambda/diary-one/actions/workflows/stat.yml/badge.svg)](https://github.com/k-l-lambda/diary-one/actions/workflows/stat.yml)
+---
+
+## Motivation
+
+This is a diary template project,
+you can write yourself diary from the branch [initial](https://github.com/k-l-lambda/diary-one/tree/initial),
+the branch offer full tool scripts and blank diary directory.
+
+
+## Usage
+
+Daily diary file name format is `YYYY/MMDD.md`, e.g. `2046/1231.md`.
+Create yourself diary file every day, or automatically do it by enabling `newDay` plug-in [here](tools/cowriter.js#L5).
+
+Aggregated memo files will be generated in the `memo/` directory, and the calendar index view will be updated in `REAMD.md`.
+
+### Avaiable script plug-ins
+
+* [Reading](tools/statReading.js)
+  For reading notes.
+
+* [Vocab](tools/statVocab.js)
+  A vocabulary list for language learning.
+
+* [Arxiv](tools/statArxiv.js)
+  A list of arxiv papers.
+
+* [Navigator](tools/navigator.js)
+  Generate a navigation bar for new diary.
+
+* [New day](tools/newDay.js)
+  Automatically create a new diary file every day.
+
+
+## Contribution
+
+There are some github [workflows](.github/workflows) to antomatically generate calendar and memo files.
+Most workflows automatically run at 04:00 every day.
+
+You can write yourself statistics script plug-ins, enable it by requiring it at [`buildStatistics.js`](tools\buildStatistics.js).
+
+We'd like to use this repository as doodle board.
+Welcome to commit diaries of anything.
+
 
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