docs(#457): add issue templates, notes on adding new icons

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,58 @@
+name: Bug report
+description: Report a problem
+type: bug
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Before reporting:
+        * search [existing issues](https://github.com/nvim-tree/nvim-web-devicons/issues)
+        * ensure that nvim-web-devicons is updated to the latest version
+
+        Please submit a Pull Request to add an icon, see [CONTRIBUTING.md](https://github.com/nvim-tree/nvim-web-devicons/blob/master/CONTRIBUTING.md)
+  - type: textarea
+    attributes:
+      label: "Description"
+      description: "A short description of the problem you are reporting."
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: "Neovim version"
+      description: "Output of `nvim --version`"
+      placeholder: |
+        NVIM v0.10.3
+        Build type: RelWithDebInfo
+        LuaJIT 2.1.1731601260
+      render: text
+    validations:
+      required: true
+  - type: input
+    attributes:
+      label: "nvim-web-devicons version"
+      description: "`cd <your-package-directory>/nvim-web-devicons.lua ; git log --format='%h' -n 1`"
+      placeholder: |
+        commit hash
+    validations:
+      required: true
+  - type: input
+    attributes:
+      label: "Operating system and version"
+      placeholder: "Linux 5.16.11-arch1-1, macOS 11.5, Windows 10"
+    validations:
+      required: true
+  - type: input
+    attributes:
+      label: "Windows variant"
+      placeholder: "WSL, PowerShell, cygwin, msys"
+    validations:
+      required: false
+  - type: textarea
+    attributes:
+      label: "Expected behavior"
+      description: "A description of the behavior you expected:"
+  - type: textarea
+    attributes:
+      label: "Actual behavior"
+      description: "Observed behavior (may optionally include images, videos or a screencast)."
+

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,22 @@
+---
+name: Feature request
+about: Suggest an idea for nvim-web-devicons
+title: ''
+type: enhancement
+assignees: ''
+
+---
+**Is this a request for a new icon?**
+Please submit a Pull Request to add an icon, see [CONTRIBUTING.md](https://github.com/nvim-tree/nvim-web-devicons/blob/master/CONTRIBUTING.md)
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is.
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

README.md

@@ -44,6 +44,20 @@ or with [lazy.nvim](https://github.com/folke/lazy.nvim)
 
 [![LuaRocks](https://img.shields.io/luarocks/v/nvim-tree/nvim-web-devicons?logo=lua&color=purple)](https://luarocks.org/modules/nvim-tree/nvim-web-devicons)
 
+## Additional Icons
+
+Additional icons may be added for icons that are present in Nerd Fonts: use the [Cheat Sheet](https://www.nerdfonts.com/cheat-sheet) search for available icons.
+
+PRs are always welcome! Please see [CONTRIBUTING](CONTRIBUTING.md)
+
+> [!IMPORTANT]
+> If the icon you need is not available on Nerd Fonts you first need to make a
+> PR to a project that feeds glyphs to Nerd Fonts. Probably the most adequate
+> project to contribute is <https://github.com/devicons/devicon>.
+> Take into account that **months** can pass before the icon is available on the
+> Nerd Fonts project, once there feel free to open a PR on this project, see 
+> [CONTRIBUTING](CONTRIBUTING.md)
+
 ## Usage
 
 ### Viewing