BUG: Update supported python version to >=3.8.0 (#133)

Author: philippesamuel

docs/user/installation.md

@@ -2,7 +2,7 @@
 There are several ways to install pdfly. The most common option is to use pip.
 
 ## pip
-pdfly requires Python 3.6+ to run.
+pdfly requires Python 3.8+ to run.
 
 Typically Python comes with `pip`, a package installer. Using it you can
 install pdfly:
@@ -28,15 +28,34 @@ pipx install pdfly
 pipx installs the pdfly application in an isolated environment. That guarantees
 that no other applications interferes with its defpendencies.
 
+## uv
+pdfly can be run without persistent installation using [uv tool run](https://docs.astral.sh/uv/guides/tools/#running-tools):
+
+```bash
+uv tool run pdfly 
+```
+
+via the [uvx](https://docs.astral.sh/uv/guides/tools/#running-tools) alias: 
+
+```bash
+uvx pdfly
+```
+
+or it can be installed using [uv tool install](https://docs.astral.sh/uv/guides/tools/#installing-tools):
+
+```bash
+uv tool install pdfly
+```
+
 ## Python Version Support
 If ✓ is given, it works. It is tested via CI.
 If ✖ is given, it is guaranteed not to work.
 If it's not filled, we don't guarantee support, but it might still work.
 
 
-| Python                 | 3.13 | 3.12 | 3.11 | 3.10 | 3.9 | 3.8 | 3.7 | 3.6 | 2.7 |
-| ---------------------- | ---- | ---- | ---- | ---- | --- | --- | --- | --- | --- |
-| pdfly                  |  ✓   |  ✓   |  ✓   |  ✓   |  ✓  |  ✓  |     |     |  ✖  |
+| Python                 | 3.13 | 3.12 | 3.11 | 3.10 | 3.9 | 3.8 | 2.7 |
+| ---------------------- | ---- | ---- | ---- | ---- | --- | --- | --- |
+| pdfly                  |  ✓   |  ✓  |  ✓   |  ✓  |  ✓  |  ✓  |  ✖  |
 
 
 ## Development Version

pyproject.toml

@@ -10,7 +10,7 @@ description = "A pure-python CLI application to manipulate PDF files"
 readme = "README.md"
 dynamic = ["version"]
 license = { file = "LICENSE" }
-requires-python = ">=3.7.0"
+requires-python = ">=3.8.0"
 
 # https://pypi.org/pypi?%3Aaction=list_classifiers
 classifiers = [
@@ -22,8 +22,6 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3 :: Only",
-    # We do not test Python 3.7 in CI, so support is not guaranteed
-    "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",