feat(search): add local search (#231)

* feat(search): add local search

* docs: add docs for search

exampleSite/content/posts/theme-documentation-basics.fr.md

@@ -209,6 +209,17 @@ Note that some of these parameters are explained in details in other sections of
   # {{< version 0.1.1 new small >}} which hash function used for SRI, when empty, no SRI is used
   # ("sha256", "sha384", "sha512", "md5")
   fingerprint = ""
+  # {{< version 0.2.0 new small >}} Search
+  [params.search]
+    enable = true
+    # type of search engine ("lunr", "algolia")
+    type = "lunr"
+    # index length of the content
+    contentLength = 5000
+    [params.search.algolia]
+      index = ""
+      appID = ""
+      searchKey = ""
   # Header info
   [params.header]
     # desktop header mode ("fixed", "normal", "auto")
@@ -460,6 +471,12 @@ Note that some of these parameters are explained in details in other sections of
     animateCSS = ''
     # {{< link "https://github.com/cferdinandi/smooth-scroll" "smooth-scroll" >}}@16.1.2
     smoothScrollJS = ''
+    # {{< version 0.2.0 new small >}} {{< link "https://github.com/algolia/autocomplete.js" "autocomplete.js" >}}@0.37.1
+    autocompleteJS = ''
+    # {{< version 0.2.0 new small >}} {{< link "https://lunrjs.com/" "lunr.js" >}}@2.3.8
+    lunrJS = ''
+    # {{< version 0.2.0 new small >}} {{< link "https://github.com/algolia/algoliasearch-client-javascript" "algoliasearch" >}}@4.1.0
+    algoliasearchJS = ''
     # {{< link "https://github.com/ellisonleao/sharer.js" "sharer" >}}@0.4.0
     sharerJS = ''
     # {{< link "https://github.com/aFarkas/lazysizes" "lazysizes" >}}@5.2.0
@@ -480,17 +497,17 @@ Note that some of these parameters are explained in details in other sections of
     katexMhchemJS = ''
     # {{< link "https://github.com/knsv/mermaid" "mermaid" >}}@8.4.8
     mermaidJS = ''
-    # {{< link "https://github.com/MoePlayer/APlayer" "aplayer" >}}@1.10.1
-    aplayerCSS = ''
-    aplayerJS = ''
-    # {{< link "https://github.com/metowolf/MetingJS" "meting" >}}@2.0.1
-    metingJS = ''
     # {{< link "https://echarts.apache.org/" "echarts" >}}@4.6.0
     echartsJS = ''
     echartsMacaronsJS = ''
     # {{< version 0.2.0 new small >}} {{< link "https://docs.mapbox.com/mapbox-gl-js" mapbox-gl >}}@1.8.1
     mapboxGLCSS = ''
     mapboxGLJS = ''
+    # {{< link "https://github.com/MoePlayer/APlayer" "aplayer" >}}@1.10.1
+    aplayerCSS = ''
+    aplayerJS = ''
+    # {{< link "https://github.com/metowolf/MetingJS" "meting" >}}@2.0.1
+    metingJS = ''
     # {{< link "https://github.com/gitalk/gitalk" "gitalk" >}}@1.6.2
     gitalkCSS = ''
     gitalkJS = ''
@@ -563,13 +580,24 @@ Note that some of these parameters are explained in details in other sections of
 
 # Options to make hugo output files
 [outputs]
-  home = ["HTML", "RSS"]
+  # {{< version 0.2.0 changed small >}}
+  home = ["HTML", "RSS", "JSON"]
   page = ["HTML", "MarkDown"]
   section = ["HTML", "RSS"]
   taxonomy = ["HTML", "RSS"]
   taxonomyTerm = ["HTML"]
 ```
 
+{{< admonition tip "Tips about CDN Configuration" >}}
+Full HTML tags or URLs are supported for CDN configuration:
+
+```toml
+smoothScrollJS = '<script src="https://cdn.jsdelivr.net/npm/smooth-scroll@16.1.3/dist/smooth-scroll.min.js" integrity="sha256-vP+F+14A1ogChQs5Osd5LJl/ci9TbzjiZjjEbcqOXrY=" crossorigin="anonymous"></script>'
+# Or
+smoothScrollJS = 'https://cdn.jsdelivr.net/npm/smooth-scroll@16/dist/smooth-scroll.min.js'
+```
+{{< /admonition >}}
+
 ![Complete configuration preview](/images/theme-documentation-basics/complete-configuration-preview.png "Complete configuration preview")
 
 ### 3.2 Favicons, Browserconfig, Manifest
@@ -738,3 +766,50 @@ Translations strings are used for common default values used in the theme. Trans
 To override these values, create a new file in your local i18n folder `i18n/<languageCode>.toml` and inspire yourself from `themes/LoveIt/i18n/en.toml`.
 
 By the way, as these translations could be used by other people, please take the time to propose a translation by [making a PR](https://github.com/dillonzq/LoveIt/pulls) to the theme!
+
+## 5 Search
+
+{{< version 0.2.0 >}}
+
+Based on [Lunr.js](https://lunrjs.com/) or [algolia](https://www.algolia.com/), searching is supported in **LoveIt** theme.
+
+### 5.1 Output Configuration
+
+In order to generate `index.json` for searching, add `JSON` output file type to the `home` of the `outputs` part in your [site configuration](#site-configuration).
+
+```toml
+[outputs]
+  home = ["HTML", "RSS", "JSON"]
+```
+
+### 5.2 Search Configuration
+
+Based on `index.json` generated by Hugo, you could activate searching.
+
+Here is the search configuration in your [site configuration](#site-configuration):
+
+```toml
+[params.search]
+  enable = true
+  # type of search engine ("lunr", "algolia")
+  type = "lunr"
+  # index length of the content
+  contentLength = 5000
+  [params.search.algolia]
+    index = ""
+    appID = ""
+    searchKey = ""
+```
+
+{{< admonition note "How to choose the type of search engine?" >}}
+* `lunr`: simple, no need to synchronize `index.json`, no limit for `contentLength`,
+  but high bandwidth and low performance (Especially for Chinese which needs a large segmentit library)
+* `algolia`: high performance and low bandwidth, but need to synchronize `index.json` and limit for `contentLength`
+{{< /admonition >}}
+
+{{< admonition tip "Tips about algolia" >}}
+You need to upload `index.json` files to algolia to activate searching.
+You could upload the `index.json` files by browsers but a script may be a better choice.
+To be compatible with Hugo multilingual mode,
+you need to upload different `index.json` for each language to the different index of algolia, such as `zh-cn/index.json` or `fr/index.json`...
+{{< /admonition >}}