add doc

.pre-commit-config.yaml

@@ -54,7 +54,7 @@
         entry: python .pre-commit-hooks/copyright-check.hook
         language: system
         files: \.(c|cc|cxx|cpp|cu|h|hpp|hxx|proto|py)$
-        exclude: (?=third_party).*(\.cpp|\.h|\.py)$
+        exclude: (?=third_party|pypinyin).*(\.cpp|\.h|\.py)$
 -   repo: https://github.com/asottile/reorder_python_imports
     rev: v2.4.0
     hooks:

docs/src/chinese_syllable.md

@@ -29,6 +29,8 @@ In the Pinyin system there are 23 initials, 24 finals, 4 tones and a neutral ton
 ## Tones
 * [Four tones](https://resources.allsetlearning.com/chinese/pronunciation/Four_tones)
 * [Neutral tone](https://resources.allsetlearning.com/chinese/pronunciation/Neutral_tone)
+* [Where do the tone marks go?](http://www.pinyin.info/rules/where.html)
+* [声调符号标在哪儿？](http://www.hwjyw.com/resource/content/2010/06/04/8183.shtml)
 
 ## Zhuyin
 * [Bopomofo](https://en.wikipedia.org/wiki/Bopomofo)

docs/src/text_front_end.md

@@ -7,6 +7,7 @@
 * [Mmseg算法](https://www.jianshu.com/p/e4ae8d194487)
 * [浅谈中文分词](http://www.isnowfy.com/introduction-to-chinese-segmentation/)
 
+* [pymmseg-cpp](https://github.com/pluskid/pymmseg-cpp.git)
 * [ustcdane/mmseg](https://github.com/ustcdane/mmseg)
 * [jkom-cloud/mmseg](https://github.com/jkom-cloud/mmseg)