Use the src/ layout to fix packaging Khoj for PyPi

- Why
  The khoj pypi packages should be installed in `khoj' directory.
  Previously it was being installed into `src' directory, which is a
  generic top level directory name that is discouraged from being used

- Changes
 - move src/* to src/khoj/*
 - update `setup.py' to `find_packages' in `src' instead of project root
 - rename imports to form `from khoj.*' in complete project
 - update `constants.web_directory' path to use `khoj' directory
 - rename root logger to `khoj' in `main.py'
 - fix image_search tests to use the newly rename `khoj' logger
 - update config, docs, workflows to reference new path `src/khoj'

setup.py

@@ -17,10 +17,10 @@ setup(
     license="GPLv3",
     keywords="search semantic-search productivity NLP org-mode markdown beancount images",
     python_requires=">=3.8, <3.11",
+    package_dir={"": "src"},
     packages=find_packages(
-        where=".",
-        exclude=["tests*"],
-        include=["src*"]
+        where="src",
+        include=["khoj*"]
     ),
     install_requires=[
         "torch == 1.13.1",
@@ -39,7 +39,7 @@ setup(
         'schedule == 1.1.0',
     ],
     include_package_data=True,
-    entry_points={"console_scripts": ["khoj = src.main:run"]},
+    entry_points={"console_scripts": ["khoj = khoj.main:run"]},
     classifiers=[
         "Development Status :: 4 - Beta",
         "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",