Add a basic migration guide

docs/make.jl

@@ -14,6 +14,7 @@ makedocs(;
         "Home" => "index.md",
         "User Guide" => "user.md",
         "Developer Guide" => "developer.md",
+        "Migrating To 0.7+" => "migrating.md",
     ],
 )
 

docs/src/index.md

@@ -21,6 +21,8 @@ If you're looking to **create new packages**, see the [User Guide](user.md).
 
 If you want to **create new plugins**, see the [Developer Guide](developer.md).
 
+if you're trying to **migrate from an older version of PkgTemplates**, see [Migrating To 0.7+](migrating.md).
+
 ### Index
 
 ```@index

docs/src/migrating.md

@@ -0,0 +1,65 @@
+```@meta
+CurrentModule = PkgTemplates
+```
+
+# Migrating To PkgTemplates 0.7+
+
+PkgTemplates 0.7 is a ground-up rewrite of the package with similar functionality but with updated APIs and internals.
+Here is a summary of things that existed in older versions but have been moved elsewhere or removed.
+However, it might be easier to just read the [User Guide](user.md).
+
+## Template keywords
+
+The recurring theme is "everything is a plugin now".
+
+| Old              | New                               |
+| :-:              | :-:                               |
+| `license="ISC"`  | `plugins=[License(; name="ISC")]` |
+| `develop=true` * | `plugins=[Develop()]`             |
+| `git=false`      | `disable_defaults=[Git]`          |
+| `ssh=true`       | `plugins=[Git(; ssh=true)]`       |
+| `manifest=true`  | `plugins=[Git(; manifest=true)]`  |
+
+\* `develop=true` was the default setting.
+
+## Plugins
+
+Aside from renamings, basically every plugin has had their constructors reworked.
+So if you are using anything non-default, you should consult the new docstring.
+
+| Old           | New                    |
+| :-----------: | :--------------------: |
+| `GitHubPages` | `Documenter{TravisCI}` |
+| `GitLabPages` | `Documenter{GitLabCI}` |
+
+## Package Generation
+
+One less name to remember!
+
+| Old                                         | New                                 |
+| :-----------------------------------------: | :---------------------------------: |
+| `generate(::Template, pkg::AbstractString)` | `(::Template)(pkg::AbstractString)` |
+
+## Interactive Templates
+
+Two less names to remember!
+
+| Old                    | New                                 |
+| :--------------------: | :---------------------------------: |
+| `interactive_template` | `Template(; interactive=true)`      |
+| `generate_interactive` | `Template(; interactive=true)(pkg)` |
+
+## Other Functions
+
+Another two less names to remember!
+Although it's unlikely that anyone used these.
+
+| Old                  | New                                                                                 |
+| :------------------: | :---------------------------------------------------------------------------------: |
+| `available_licenses` | [GitHub](https://github.com/invenia/PkgTemplates.jl/tree/master/templates/licenses) |
+| `show_license`       | [GitHub](https://github.com/invenia/PkgTemplates.jl/tree/master/templates/licenses) |
+
+## Custom Plugins
+
+In addition to the changes in usage, custom plugins from older versions of PkgTemplates will not work in 0.7+.
+See the [Developer Guide](developer.md) for more information on the new extension API.