docs: update links to new Tera docs URL (getzola#2289)

More context here: Keats/tera#854 (comment)

Author: oscard0m

docs/content/documentation/content/shortcodes.md

@@ -16,7 +16,7 @@ The latter may also be solved by writing HTML, however Zola allows the use of Ma
 rather than `.html`. This may be particularly useful if you want to include headings generated by the shortcode in the
 [table of contents](@/documentation/content/table-of-contents.md).
 
-If you want to use something similar to shortcodes in your templates, you can use [Tera macros](https://tera.netlify.com/docs#macros). They are functions or components that you can call to return some text.
+If you want to use something similar to shortcodes in your templates, you can use [Tera macros](https://keats.github.io/tera/docs#macros). They are functions or components that you can call to return some text.
 
 ## Writing a shortcode
 Let's write a shortcode to embed YouTube videos as an example.

docs/content/documentation/getting-started/directory-structure.md

@@ -44,7 +44,7 @@ If your static files are large, you can configure Zola to [hard link](https://en
 instead of copying them by setting `hard_link_static = true` in the config file.
 
 ## `templates`
-Contains all the [Tera](https://tera.netlify.com) templates that will be used to render your site.
+Contains all the [Tera](https://keats.github.io/tera) templates that will be used to render your site.
 Have a look at the [templates documentation](@/documentation/templates/_index.md) to learn more about default templates
 and available variables.
 

docs/content/documentation/getting-started/overview.md

@@ -5,7 +5,7 @@ weight = 5
 
 ## Zola at a Glance
 
-Zola is a static site generator (SSG), similar to [Hugo](https://gohugo.io/), [Pelican](https://blog.getpelican.com/), and [Jekyll](https://jekyllrb.com/) (for a comprehensive list of SSGs, please see [Jamstack](https://jamstack.org/generators)). It is written in [Rust](https://www.rust-lang.org/) and uses the [Tera](https://tera.netlify.com/) template engine, which is similar to [Jinja2](https://jinja.palletsprojects.com/en/2.10.x/), [Django templates](https://docs.djangoproject.com/en/2.2/topics/templates/), [Liquid](https://shopify.github.io/liquid/), and [Twig](https://twig.symfony.com/).
+Zola is a static site generator (SSG), similar to [Hugo](https://gohugo.io/), [Pelican](https://blog.getpelican.com/), and [Jekyll](https://jekyllrb.com/) (for a comprehensive list of SSGs, please see [Jamstack](https://jamstack.org/generators)). It is written in [Rust](https://www.rust-lang.org/) and uses the [Tera](https://keats.github.io/tera/) template engine, which is similar to [Jinja2](https://jinja.palletsprojects.com/en/2.10.x/), [Django templates](https://docs.djangoproject.com/en/2.2/topics/templates/), [Liquid](https://shopify.github.io/liquid/), and [Twig](https://twig.symfony.com/).
 
 Content is written in [CommonMark](https://commonmark.org/), a strongly defined, highly compatible specification of [Markdown](https://www.markdownguide.org/). Zola uses [pulldown-cmark](https://github.com/raphlinus/pulldown-cmark#pulldown-cmark) to parse markdown files. The goal of this library is 100% compliance with the CommonMark spec. It adds a few additional features such as parsing footnotes, Github flavored tables, Github flavored task lists and strikethrough.
 

docs/content/documentation/templates/overview.md

@@ -3,7 +3,7 @@ title = "Overview"
 weight = 10
 +++
 
-Zola uses the [Tera](https://tera.netlify.com) template engine, which is very similar
+Zola uses the [Tera](https://keats.github.io/tera) template engine, which is very similar
 to Jinja2, Liquid and Twig.
 
 As this documentation will only talk about how templates work in Zola, please read
@@ -62,7 +62,7 @@ Custom templates are not required to live at the root of your `templates` direct
 For example, `product_pages/with_pictures.html` is a valid template.
 
 ## Built-in filters
-Zola adds a few filters in addition to [those](https://tera.netlify.com/docs/#filters) already present
+Zola adds a few filters in addition to [those](https://keats.github.io/tera/docs/#filters) already present
 in Tera.
 
 ### markdown
@@ -113,7 +113,7 @@ To format a number for a specific locale, you can use the `locale` argument and
 
 ## Built-in functions
 
-Zola adds a few Tera functions to [those built-in in Tera](https://tera.netlify.com/docs#built-in-functions)
+Zola adds a few Tera functions to [those built-in in Tera](https://keats.github.io/tera/docs#built-in-functions)
 to make it easier to develop complex sites.
 
 ### File searching logic

docs/content/documentation/themes/creating-a-theme.md

@@ -4,7 +4,7 @@ weight = 30
 +++
 
 Creating a theme is exactly like creating a normal site with Zola, except you
-will want to use many [Tera blocks](https://tera.netlify.com/docs#inheritance) to
+will want to use many [Tera blocks](https://keats.github.io/tera/docs#inheritance) to
 allow users to easily modify it.
 
 ## Getting started