docs: rename repository from oil.nvim to canola.nvim

Problem: the fork shared the same name as upstream, making it difficult
to distinguish and discover independently.

Solution: rename the repository to canola.nvim — a type of oil, making
the lineage obvious while establishing a distinct identity. Update all
references in the README, rockspec, and issue templates.

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -9,7 +9,7 @@ body:
       options:
         - label:
             I have searched [existing
-            issues](https://github.com/barrettruth/oil.nvim/issues)
+            issues](https://github.com/barrettruth/canola.nvim/issues)
           required: true
         - label: I have updated to the latest version
           required: true
@@ -69,7 +69,7 @@ body:
         require('lazy.nvim').setup({
           spec = {
             {
-              'barrettruth/oil.nvim',
+              'barrettruth/canola.nvim',
               init = function()
                 vim.g.oil = {}
               end,

.github/ISSUE_TEMPLATE/config.yaml

@@ -1,5 +1,5 @@
 blank_issues_enabled: false
 contact_links:
   - name: Questions
-    url: https://github.com/barrettruth/oil.nvim/discussions
+    url: https://github.com/barrettruth/canola.nvim/discussions
     about: Ask questions and discuss ideas

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -9,7 +9,7 @@ body:
       options:
         - label:
             I have searched [existing
-            issues](https://github.com/barrettruth/oil.nvim/issues)
+            issues](https://github.com/barrettruth/canola.nvim/issues)
           required: true
 
   - type: textarea